1 <a href="#basics">Basics</a><br>
2 <a href="#ximian">The Ximian Role in the Mono project</a><br>
3 <a href="#gnome">Mono and GNOME</a><br>
4 <a href="#gui">Building GUI applications with Mono</a><br>
5 <a href="#msft">Mono and Microsoft</a><br>
6 <a href="#platforms">Mono platforms</a><br>
7 <a href="#pnpproject">Mono and the Portable.NET Project</a><br>
8 <a href="#webservices">Web Services</a><br>
9 <a href="#asp">Mono and ASP.NET</a><br>
10 <a href="#ado">Mono and ADO.NET</a><br>
11 <a href="#monodoc">MonoDoc</a><br>
12 <a href="#devel">Development Tools and Issues</a><br>
13 <a href="#java">Mono and Java</a><br>
14 <a href="#extending">Extending Mono</a><br>
15 <a href="#portability">Portability</a><br>
16 <a href="#reuse">Reusing Existing Code</a><br>
17 <a href="#gcc">Mono and GCC</a><br>
18 <a href="#performance">Performance</a><br>
19 <a href="#licensing">Licensing</a><br>
20 <a href="#patents">Patents</a><br>
21 <a href="#etc">Miscellaneous Questions</a><br>
22 <a href="#problems">Mono Common Problems</a><br>
25 href="http://www.es.gnome.org/documentacion/articulos/mono-puf/mono-puf/">Spanish
26 translation</a> is also available
31 Q: What is Mono exactly?
33 A: The Mono Project is an open development initiative sponsored by
34 Ximian that is working to develop an open source, Unix
35 version of the Microsoft .NET development platform. Its objective
36 is to enable Unix developers to build and
37 deploy cross-platform .NET Applications. The project will
38 implement various technologies developed by Microsoft that have now
39 been submitted to the ECMA for standardization.
41 Q: What is the difference between Mono and the .NET Initiative?
43 A: The ".NET Initiative" is a somewhat nebulous company-wide effort by
44 Microsoft, one part of which is a cross-platform development
45 framework. Mono is an implementation of the development framework,
46 but not an implementation of anything else related to the .NET
47 Initiative, such as Passport, software-as-a-service, or
48 corporate re-branding.
50 Q: What technologies are included in Mono?
52 A: Mono contains a number of components useful for building new
56 * A Common Language Infrastructure (CLI) virtual
57 machine that contains a class loader, Just-in-time
58 compiler, and a garbage collecting runtime.
60 * A class library that can work with any language
61 which works on the CLR.
63 * A compiler for the C# language. In the future we
64 might work on other compilers that target the Common
69 Windows has compilers that target the virtual machine from <a
70 href="http://msdn.microsoft.com/net/thirdparty/default.asp#lang">a
71 number of languages:</a> Managed C++, Java Script, Eiffel,
72 Component Pascal, APL, Cobol, Perl, Python, Scheme,
73 Smalltalk, Standard ML, Haskell, Mercury and Oberon.
75 The CLR and the Common Type System (CTS) enables applications and
76 libraries to be written in a collection of different languages that
79 This means for example that if you define a class to do algebraic
80 manipulation in C#, that class can be reused from any other
81 language that supports the CLI. You could create a class in C#,
82 subclass it in C++ and instantiate it in an Eiffel program.
84 A single object system, threading system, class libraries, and
85 garbage collection system can be shared across all these languages.
87 Q: Where can I find the specification for these technologies?
89 A: You can find the information here:
92 C# <a href="http://www.ecma.ch/ecma1/STAND/ecma-334.htm">http://www.ecma.ch/ecma1/STAND/ecma-334.htm</a>
94 CLI <a href="http://www.ecma.ch/ecma1/STAND/ecma-335.htm">http://www.ecma.ch/ecma1/STAND/ecma-335.htm</a>
96 Q: Will you implement the .NET Framework SDK class libraries?
98 A: Yes, we will be implementing the APIs of the .NET Framework SDK
101 Q: Will you offer an ECMA-compliant set of class libraries?
103 A: Eventually we will. Our current focus is on inter-operating
104 with the Microsoft SDK, but we will also offer an ECMA compliant
107 Q: What does the name "Mono" mean?
109 A: Mono is the word for `monkey' in Spanish. We like monkeys.
113 A: The JIT engine is usable on Intel x86 machines. An interpreter
114 can be used on other non-Intel x86 machines.
116 The class libraries are mature enough to run some real applications
117 (the compiler for instance, and every day more and more applications
118 are natively developed with Mono).
120 Q: When will you ship it?
122 A: Different parts of Mono will achieve usability at different stages,
123 once we are comfortable with the compiler, we will release "Mono Core",
124 which contains everything needed to develop applications with the base
125 class libraries, this will happen soon and in the meantime you can
126 download daily snapshots of our work. Also the full ASP.NET support is
129 Other higher level class libraries (ASP.NET, ADO.NET, WinForms) will
130 be released when they become stable.
132 Q: What major components will you include in Mono?
134 A: Hopefully everything that Microsoft ships on their Framework
135 (ADO.NET, ASP.NET, WinForms), and we encourage third party developers to
136 create reusable components that work on both Mono and Windows.
138 Q: How can I contribute?
140 A: Check the <a href="contributing.html">contributing</a> section.
142 Q: Aren't you just copying someone else's work?
144 A: We are interested in providing the best tools for programmers to
145 develop applications for Free Operating Systems. We also want to help
146 provide the interoperability that will allow those systems to fit in
147 with other standards.
149 For more background, read the <a href="http://www.go-mono.com/rationale.html">Mono
150 Project white paper</a>.
153 Q: Miguel said once that Mono was being implemented in COBOL. Is that true?.
155 A: No. It was a joke.
158 <a name="ximian"></a>
160 ** The Ximian Role in the Mono Project
162 Q: Why is Ximian working on .NET?
164 A: Ximian is interested in providing the best tools for programmers to
165 develop applications for Free Operating Systems.
167 For more information, read the project <a
168 href="rationale.html">rationale</a> page.
170 Q: Will Ximian be able to take on a project of this size?
172 A: Of course not. Ximian a supporter of the Mono project, but the only way
173 to implement something of this size is for the entire free software
174 community to get involved. Visit the <a href="contributing.html">contributing</a>
175 page if you'd like to help out.
177 Q: What pieces will Ximian be working on?
179 A: We will devote most of our resources to work on the pieces which are
180 on the critical path to release a development and execution
181 environment. Once the project is at a stage where it is useful in
182 the real world, it will achieve a critical mass of developers to
185 Q: Will Ximian offer Mono commercially?
187 A: When Mono is ready to be shipped Ximian will offer a commercial
188 support and services for Mono.
190 Q: Does Ximian provide consulting services around Mono?
192 A: Yes, Ximian does provide consulting services around Mono to
193 make it suitable to your needs. Porting the runtime engine,
194 customizing it, working on specific classes or tuning the code
195 for your particular needs.
197 Q: Will you wait until Mono is finished?
199 A: Mono will ship on various stages as they mature. Some people
200 require only a subset of the technologies, those will ship first.
202 More advanced features will take more time to develop. A support
203 time line will be available in June 2002.
208 Q: How is Mono related to GNOME?
210 A: In a number of ways. This project was born out of the need of
211 providing improved tools for the GNOME community, and will use
212 existing components that have been developed for GNOME when they
213 are available. For example, we plan to use Gtk+ and Libart to
214 implement Winforms and the Drawing2D API and are considering
217 Q: Has the GNOME Foundation or the GNOME team adopted Mono?
219 A: Mono is too new to be adopted by those groups. We hope that the
220 tools that we will provide will be adopted by free software
221 programmers including the GNOME Foundation members and the GNOME
224 Q: Should GNOME programmers switch over to Mono now?
226 A: It is still far to early for discussions of "switching over." No
227 pieces of Mono will be ready within the next six months, and a
228 complete implementation is roughly one year away.
230 We encourage GNOME developers to continue using the existing tools,
231 libraries and components. Improvements made to GNOME will have an
232 impact on Mono, as they would be the "back-end" for various classes.
234 Q: Will Mono include compatibility with Bonobo components? What is the
235 relationship between Mono and Bonobo?
237 A: Yes, we will provide a set of classes for implementing and using
238 Bonobo components from within Mono. Mono should allow you to write
239 Bonobo components more easily, just like .NET on Windows allows you
240 to export .NET components to COM.
242 Q: Does Mono depend on GNOME?
244 A: No, Mono does not depend on GNOME. We use a few packages produced by
245 the GNOME team like the `glib' library.
247 Q: But will I be able to build GNOME applications?
249 A: Yes, we will enable people to write GNOME applications using Mono.
251 Q: Do you have C# bindings for GNOME?.
253 A: Yes, we currently bind libgnome, libgnomecanvas, and libgnomeui --
254 although I dare say I have no idea how functional the bindings are
255 outside of what I tested in the sample app. I imagine other libraries
256 under the GNOME framework will be added on an as-needed (and as-requested)
257 basis...although a truly good bonobo binding will have to wait on the CORBA
258 remoting support which has been started recently.
263 Q: Will Mono enable GUI applications to be authored?
265 A: Yes, you will be able to build GUI applications. Indeed, that is our
266 main focus. We will provide both the Windows.Forms API and the Gtk# API.
268 Q: What is the difference between Gtk# and System.Windows.Forms?
270 A: Gtk# is a set of bindings for the Gtk+ toolkit for C# (and other
271 CIL-enabled languages). System.Windows.Forms is an API defined
272 by Microsoft to build GUI applications.
274 Q: Will I be able to run my smart clients on systems powered by Mono?
276 A: As long as your applications are 100% .NET and do not make use
277 of P/Invoke to call Win32 functions, your smart client applications
278 will run on Mono platforms.
280 Q: Where can I learn more about Gtk#?
282 A: The following <a href="http://gtk-sharp.sourceforge.net>link</a> sends you to the page of the project.
284 Q: What can I do with Gtk#?.
286 A: Gtk# is becoming very usable and you can create applications and
287 applets like those you see in a GNOME desktop environment. It's
288 easy to install so it's worth a try.
290 Q: How can I compile my HelloWorld.cs which uses Gtk#?.
292 A: Try: mcs --unsafe -o HelloWorld.exe -r glib-sharp -r pango-sharp -r
293 atk-sharp -r gdk-sharp -r gtk-sharp -r gdk-imaging-sharp
296 Q: Is there any way how to connect DataAdapter to some GTK# controls?
298 A: There is a sample file called `DbClient' in gtk-sharp/samples that you
299 might to look at. It is a sample program in Gtk# that adds/updates/deletes
300 information on a Postgress database. When we have the new table/tree widgets,
301 I am sure someone would write an adapter for System.Data (in Gtk2 the
302 tree/list widgets are written using a view/model, so you only need to write
303 a model that maps to the database). You can have a look at
304 gtk-sharp/sample/DbClient, where there is a GTK# application that uses
305 System.Data. It does not use DataAdapter, but DataReader though.
307 Q: Do you have an estimate for when Windows.Forms will be released?
309 A: We do not know, volunteers are working on this, but there is no set
310 date yet. The current approach is using the Wine Library to implement
314 ** Mono and Microsoft
316 Q: Is Microsoft helping Ximian with this project?
318 A: There is no high level communication between Ximian and Microsoft
319 at this point, but engineers who work on .NET or the ECMA groups
320 have been very friendly, and very nice to answer our questions, or
321 clarify part of the specification for us.
323 Microsoft is interested in other implementations of .NET and are
324 willing to help make the ECMA spec more accurate for this purpose.
326 Ximian was also invited to participate in the ECMA committee
327 meetings for C# and the CLI.
329 Q: Is Microsoft or Corel paying Ximian to do this?
333 Q: Do you fear that Microsoft will change the spec and render Mono
336 A: No. Microsoft proved with the CLI and the C# language that it was
337 possible to create a powerful foundation for many languages to
338 inter-operate. We will always have that.
340 Even if changes happened in the platform which were undocumented,
341 the existing platform would a value on its own.
343 Q: Are you writing Mono from the ECMA specs?
345 A: Yes, we are writing them from the ECMA specs and the published
346 materials in print about .NET.
348 Q: If my applications use Mono, will I have to pay a service fee?
350 A: No. Mono is not related to Microsoft's initiative of
351 software-as-a-service.
353 Q: Is the Mono Project is related to the Microsoft Hailstorm effort? Is
354 Ximian endorsing Hailstorm?
356 A: No. The Mono Project is focused on providing a compatible set of
357 tools for the Microsoft .NET development platform. It does not
358 address, require, or otherwise endorse the MS Passport-based
359 Hailstorm single sign-on system that is part of Windows XP and
362 Q: Will Mono or .NET applications depend on Microsoft Passport?
364 A: No. MS Passport is unrelated to running .NET compatible applications
365 produced with the Mono tools. The only thing you will need is a
366 just-in-time compiler (JIT).
368 Q: What is a 100% .NET application?
370 A: A `100% .NET application' is one that only uses the APIs defined
371 under the System namespace and does not use PInvoke. These
372 applications would in theory run unmodified on Windows, Linux,
373 HP-UX, Solaris, MacOS X and others.
375 Q: If Microsoft will release a port of their .NET platform under the
376 `Shared Source' license, why should I bother with anything else?
378 A: The Shared Source implementation will be expensive and its uses
379 will be tightly restricted, especially for commercial use. We are
380 working towards an implementation that will grant a number of
381 important rights to recipients: use for any purpose,
382 redistribution, modification, and redistribution of modifications.
384 This is what we call <a
385 href="http://www.gnu.org/philosophy/free-sw.html">Free Software</a>
387 Q: Is Mono a free implementation of Passport?
389 A: No. Mono is just a runtime, a compiler and a set of class
392 Q: Will the System.Web.Security.PassportIdentity class mean
393 that my software will depend on Passport?
395 A: No. Applications may use that API to contact a Passport site, but
396 are not required to do so.
398 As long as your application does not use Passport, you will not
401 Q: Will Mono running on Linux make Passport available for Linux?
403 A: No. However, the Passport toolkit for Linux-based web servers is
404 available from Microsoft.
406 Q: Will Mono allow me to run Microsoft Office on Linux?
408 A: No, it will not. Microsoft Office is a Windows application. To
409 learn more about running Windows applications on Intel Unix systems
410 refer to <a href="http://www.winehq.com">the Wine Project</a>.
412 Q: Will I be able to compile a Microsoft VB.NET application and execute
413 the resultant MSIL file under MONO on Linux without converting to C#
416 A: Once we have a complete VisualBasic runtime, yes.
418 Q: Can mono run the WebMatrix?
420 A: No. That requires System.Windows.Forms support which is not
421 currently implemented.
423 Q: Does mono have something like Passport?
424 Will mono have a server side Passport/Similar framework for XSP as well as client classes?
426 A: Not yet, but the client side API for authentication is not the problem.
427 We will likely have a lot of other authentication APIs, like the Liberty
428 Alliance APIs. The problem is people on the web provider end that might use
429 this for authentication.
431 <a name="platforms"></a>
434 Q: What operating systems does Mono run on?
436 A: Mono is known to run on Linux, Unix and Windows systems.
438 Q: What architectures does Mono support?
440 A: Mono today ships with a Just-in-Time compiler for x86-based
441 systems. It is tested regularly on Linux, FreeBSD and Windows
442 (with the XP/NT core).
444 There is also an interpreter, which is slower that runs on the
445 s390, SPARC and PowerPC architectures.
447 Q: Can Mono run on Windows 9x, or ME editions?
449 A: Mono requires Unicode versions of Win32 APIs to run,
450 and only a handful of *W functions is supported under Win9x.
452 There is Microsoft Layer for Unicode that provides implementation
453 of these APIs on 9x systems.
455 Unfortunately it uses linker trick for delayed load that is not
456 supported by ld, so some sort of adapter is necessary.
458 You will need MSLU and one of the following libs to link Mono to
460 href="http://mono.eurosoft.od.ua/files/unimono.zip">http://mono.eurosoft.od.ua/files/unimono.zip</a>
461 or alternatively search the net for "libunicows".
463 No changes to Mono source code required, the only thing is to make
464 sure that linker will resolve imports to adapter library instead of
465 Win32 libs. This is achieved by inserting -lunimono before
466 -lkerner32/user32 in the linker's specs file.
469 <a name="pnpproject"></a>
470 ** Mono and Portable.NET
472 Q: What are the differences between Mono and Portable.NET?
474 A: Most of Mono is being written using C#, with only
475 a few parts written in C (The JIT engine, the runtime, the
476 interfaces to the garbage collection system).
478 It is easier to describe what is unique about Mono:
480 <li> A Just-in-Time compiler engine. This is important for
481 making your applications fast.
483 <li> A self-hosting C# compiler written in C#, which is clean, easy
486 <li> Focus on the .NET Framework: we are tracking down the .NET
487 Framework API definition, as we believe it is the API people
488 will be most familiar with.
490 <li> A multi-platform runtime engine: both a JIT engine and an
491 interpreter exist. The JIT engine runs currently on x86
492 systems, while the interpreter works on SPARC, StrongARM,
493 s390 and PowerPC systems.
495 <li> Supports Linux, Windows and Solaris at this point.
497 <li> The JIT engine is written using a portable instruction
498 selector which not only generates good code (we are told
499 that we are faster than Rotor, but it is hard to tell) but
500 is also the foundation to re-target the JIT engine to other
503 The system employed is described in various compiler
504 books and it is very similar to what is described in the
505 book that covers LCC, the ANSI C retargetable C compiler.
507 <li> The JIT engine supports in-lining, constant folding and propagation,
509 <li> Full support for remoting in the runtime, but the class
510 libraries are still behind.
512 <li> The C# compiler, the JIT engine and the class libraries are
513 mature enough that the whole system is self-hosting. This means that
514 we develop Mono completely with itself at this point.
516 <li> We are not yet done, and there is a lot of work left to be
519 <li> We have a great community of developers, without which Mono
520 would not be possible.
522 <li> We are working on an ahead of time compilation mode to
523 pre-compile code for the target architecture (this is part
524 of our new code generation effort).
527 <a name="webservices"></a>
530 Q: How is Mono related to Web Services?
532 A: Mono is only related to Web Services in that it will implement the
533 same set of classes that have been authored in the .NET Framework
534 to simplify and streamline the process of building Web Services.
536 But most importantly, Mono is an Open Source implementation of the
539 Q: Can I author Web Services with Mono?
541 A: You will be able to write Web Services on .NET that run on Mono and
544 Q: If Mono implements the SDK classes, will I be able to write and
545 execute .NET Web Services with it?
547 A: Yes. When the project is finished, you will be able to use the
548 same technologies that are available through the .NET Framework SDK
549 on Windows to write Web Services.
551 Q: What about Soup? Can I use Soup without Mono?
553 A: Soup is a library for GNOME applications to create SOAP servers and
554 SOAP clients, and can be used without Mono. You can browse the
555 source code for soup using <a
556 href="http://cvs.gnome.org/bonsai">GNOME's Bonsai</a>.
560 A: Yes. The CLI contains enough information about a class that
561 exposing it to other RPC systems (like CORBA) is really simple, and
562 does not even require support from an object.
564 <a href="http://remoting-corba.sourceforge.net/">Remoting.CORBA</a> is
565 a CORBA implementation that is gaining momentum.
567 Building an implementation of the Bonobo interfaces once this is ready
568 should be relatively simple.
570 Q: Can I serialize my objects to other things other than XML?
572 A: Yes, although the serializing tools have not yet been planned, and
573 you would probably have to implement them yourself.
575 Q: Will Mono use ORBit?
577 A: There are a few advantages in using ORBit, like reusing existing code
578 and leveraging all the work done on it. Michael Meeks has posted
579 a few <a href="http://lists.ximian.com/archives/public/mono-list/2002-September/008592.html">reasons</a>,
580 as well as some <a href="http://lists.ximian.com/archives/public/mono-list/2002-September/008657.html">ideas</a>
581 that could be used to reuse ORBit.
583 Most users are likely to choose a native .NET solution, like <a href="http://cvs.gnome.org/bonsai">Remoting.CORBA</a>
586 <a name="monodoc"></a>
591 A: MonoDoc is a graphical documentation editor and viewer. Currently, MonoDoc
592 consists of a Gtk# application and is in heavy development. There is also a
597 ** Development Tools and Issues
599 Q: Will it be possible to use the CLI features without using byte codes
602 A: Yes. The CLI engine will be made available as a shared library.
603 The garbage collection engine, the threading abstraction, the
604 object system, the dynamic type code system and the JIT will be
605 available for C developers to integrate with their applications if
608 Q: Will you have new development tools?
610 A: With any luck, Free Software enthusiasts will contribute tools to
611 improve the developer environment. These tools could be developed
612 initially using the Microsoft implementation of the CLI and then
613 executed later with Mono.
615 Q: What kind of rules make the Common Intermediate Language useful for
618 A: The main rule is that the stack in the CLI is not a general purpose
619 stack. You are not allowed to use it for other purposes than
620 computing values and passing arguments to functions or return
623 At any given call or return instruction, the types on the stack
624 have to be the same independently of the flow of execution of your
627 Q: Is it true that the CIL is ideal for JITing and not efficient for
630 A: The CIL is better suited to be JITed than JVM byte codes, but you
631 can interpret them as trivially as you can interpret JVM byte
634 Q: Isn't it a little bit confusing to have the name of "XSP" (the same
635 as in the Apache Project) for the ASP.NET support in Mono?.
637 A: In Mono, xsp is just the name of the C# code generator for ASP.NET
638 pages. In the Apache Project, it is a term for the "eXtensible Server
639 Pages" technology so as they are very different things, they don't
642 Q: What about using something like Jabber instead of the System.Messaging
645 A: In short, MSMQ is not something like Jabber, but asynchronous messaging
646 through queues. Useful queues do more than serialize messages, they are
647 also platform bridges.
649 Q: Are you supporting XMLDocument and relatives?.
651 A: Currently, we aren't implementing them yet. It would require updates to
652 most of the XmlNode derivatives so it's not a trivial task. We are
653 currently focusing on getting XPath support working.
655 Q: Is there any plan to develop an aspx server for Mono?.
657 A: The web server turned out to be very simple compared to the rest of the
658 work. Gonzalo has got the page generator mostly done (a module called
659 xsp, who has nothing to do with the XSP term used in the Apache Project).
660 Patrik has done a lot of the work to get the ProcessRequest to work.
661 You can try to help in the final touches to the System.Web classes and
662 writing regression tests for the widgets we have.
664 Q: Is there any way I can develop the class libraries using Linux yet?
666 A: Yes. Some class libraries can be developed on Linux. Search for
667 Paolo's post (he lists which classes can be compiled fine now).
669 Q: Is there any way I can install a known working copy of mono in /usr,
670 and an experimental copy somewhere else, and have both copies use
671 their own libraries? (I'm still not very good at library paths in
674 A: Yes. Just use two installation prefixes.
676 Q: How should I write tests or a tests suite?
678 A: If you do a test suite for C#, you might want to keep it
679 independent of the Mono C# compiler, so that other compiler
680 implementations can later use it.
682 Q: Would it be too terrible to have another corlib signed as mscorlib?
684 A: We rename corlib to mscorlib also when saving the PE files, in fact,
685 the runtime can execute program created by mono just fine.
687 Q: Is there a relatively straightforward way to repeat the steps taken
688 by Paolo to get Mono completely self-hosted on Linux?
690 A: To build the compiler and class libraries in Linux, run:
691 <ul><li>make -f makefile.gnu. To install them, run: </li>
692 <li>make -f makefile.gnu install prefix=/opt/mono</li>
695 If you want to produce and distribute a monocharge tarball, run:
696 make -f makefile.gnu dist
697 Of course you have to run these in the top level mcs directory.
699 Q: Is it possible to build a C# file to some sort of intermediate format which
700 can linked into a final module, like the traditional .c -> .o -> .so path?
702 A: You could do: mcs /target:module file1.cs, mcs /target:module file2.cs,
703 mcs /target:exe file1.dll file2.dll /out:mybin.exe
705 Q: Is there any plans for implementing remoting in the near future?, When will
706 work in System.Runtime.Remoting.dll start?
708 A: The remoting infrastructure is in place. Some of the channels and
711 Q: I'm wondering if there are any plans to start using nant to build the
712 class lib + test lib. i think that every project need/should use an
713 automated build process and nant + a couple of tools enables this. is
714 the problem that the compiler can't run nant yet?
716 A: Maybe well be doing some sort of automated build process + testing when
719 Q: My C code uses the __stdcall which is not availble on Linux, how can I
720 make the code portable Windows/Unix across platforms?
722 A: Replace the __stdcall attribute with the STDCALL macro, and include this
723 in your C code for newer gcc versions:
726 #define STDCALL __attribute__((stdcall))
732 Q: Does Mono support ASP.NET?
736 Mono supports ASP.NET, we have shown an unmodified IBuySpy
737 installation running on Mono as well as various other programs. You can
738 try it yourself downloading the XSP server.
740 Q: Do I need install cygwin to work on ASP.NET in mono or Linux is enough since
741 it is self host right now.
745 Q: How can I run ASP.NET-based applications with Mono?
747 A: You need the Mono runtime and a hosting web server. Currently we distribute a
748 small web server called `xsp' which is used to debug applications, or you can choose
749 to use Daniel's Apache 2 module.
751 Q: Any plan to make ASP.NET in mono works with Apache in Linux?.
753 A: Daniel has authored an Apache2 Module for Mono that hosts the ASP.NET runtime
754 and is available here: <a
755 href="http://apacheworld.org/modmono/">http://apacheworld.org/modmono/</a>
757 Q: Will you support Apache 1?
759 A: Modules developed for Apache 2 are not compatible with Apache 1.3
760 Daniel plans to support Apache 1.3 in the future but the current focus is on
761 Apache 2, because of the better support for threading and Windows.
763 Q: Can I run Apache 1 and Apache 2 on the same machine?
765 You can always keep a copy of Apache 2 running in paralell with your Apache
766 1.3 (either different port or using a reverse proxy).
768 You can also bind the two servers to different IP addresses on the
769 same physical machine.
774 Q: What is the status of ADO.NET support?. Could I start migrating
775 applications from MS.NET to Mono?.
777 A: You could start right now using the ADO.NET support in mono, of course,
778 if you want to help filling the missing gaps while you develop your app
779 :-) Well, what I mean is that we're not that far to having full ADO.NET
780 support in Mono, and we've got a lot of working things, so if we could
781 get more help, we'd finish it really soon :-)
783 Q: In developing the data architecture for the application are there and
784 objects I should stay away from in order to insure the smoothest possible
785 transition (minimum code rewrite) to Mono's ADO.NET implementation? (For
786 example, strongly typed datasets versus untyped datasets, etc...)
788 A: We are implementing all the classes in Microsoft .NET's System.Data, so
789 you can be sure that things will work the same in Mono as with the Microsoft
792 Q: Does Mono can to connect to Sybase by using Mono.Data.*?
794 A: Yes. use Mono.Data.SybaseClient. First of all you have to create a
795 SybaseConnection, and then, from it, use it as any other
796 IDbConnection-based class.
801 Q: Why don't you use Java? After all, there are many languages that
804 A: You can get very good tools for doing Java development on free
805 systems right now. <a href="http://www.redhat.com">Red Hat</a> has
806 contributed a <a href="http://gcc.gnu.org">GCC</a> <a
807 href="http://gcc.gnu.org/java">front-end for Java</a> that can take
808 Java sources or Java byte codes and generate native executables; <a
809 href="http://www.transvirtual.com">Transvirtual</a> has implemented
810 <a href="http://www.kaffe.org">Kaffe</a> a JIT engine for Java;
811 Intel also has a Java VM called <a
812 href="http://www.intel.com/research/mrl/orp">ORP</a>.
814 The JVM is not designed to be a general purpose virtual machine.
815 The Common Intermediate Language (CIL), on the other hand, is
816 designed to be a target for a
817 wide variety of programming languages, and has a set of rules
818 designed to be optimal for JITers.
820 Q: Could Java target the CLI?
822 A: Yes, Java could target the CLI. We have details on a <a
823 href="ideas.html#guavac">project</a> that someone could take on to
826 Microsoft has an implementation of the Java language called J# that
827 can target the CIL execution engine.
829 Q: Is it possible to write a JVM byte code to CIL converter?
831 A: Yes, it is possible. Here are a few starting point:
834 * A byte code representation is really a flattened forest of
835 trees. Look at the Mono JIT engine to see how we compute
836 the basic blocks (this is used to figure out the "trees").
838 The forest is just an array of trees.
840 Indeed, run the JIT engine with -d (mono -d prog.exe) and
841 you will see how these trees look like.
843 You will have to do something similar for Java.
845 * Each "forest of trees" has a meaning. This meaning can now
846 be translated into the equivalent "meaning" in CLR-land.
849 Q: Could mono become a hybrid CIL/java platform?
851 A: No. It is quite far from the philosophy of the project. The idea of Mono
852 is, to have only _one_ VM, on which all can run. And if there existing a
853 binary-converter from Java-.class to IL and if there existing something
854 like J-Sharp on Mono, you can write programs in Java, which than can run
855 on Mono. You do not need two bindings (like your example: GTK-Sharp _and_
856 Java-Gnome). You need only _one_ of it (GTK-Sharp). Thats the idea of Mono.
857 An other point is, that there are no people, who use Open Source-JVMs. They
858 all prefer Suns original. But for Unix there don't exist a .NET-Framework.
859 So it is possible, that in the future Mono is the standard .NET for Unixes.
861 Q: Do you plan to implement a Javascript compiler?
863 A: Yes. Eto Demerzal has started a Rhino port to C#.
864 After this is completed, we will begin developing
865 the JavaScript compiler.
867 Q: Can Mono or .NET share system classes (loaded from mscore.dll and other
868 libs) or will it behave like Sun's Java VM?
870 A: What you can do with mono is to load different applications in their own
871 application domain: this is a feature of the CLR that allows sandboxing
872 applications inside a single process space. This is usualy exploited to
873 compartmentalize different parts of the same app, but it can also be
874 effectively used to reduce the startup and memory overhead.
875 Using different appdomains the runtime representation of types and
876 methods is shared across applications.
878 <a name="extending"></a>
881 Q: Would you allow other classes other than those in the
884 A: Yes. The Microsoft class collection is very big, but it is by no
885 means complete. It would be nice to have a port of `Camel' (the
886 Mail API used by Evolution inspired by Java Mail) for Mono
889 You might also want to look into implementing CORBA for Mono. Not
890 only because it would be useful, but because it sounds like a fun
891 thing to do, given the fact that the CLI is such a type rich
894 For more information on extending Mono, see our <a
895 href="ideas.html">ideas</a> page.
897 Q: Do you plan to Embrace and Extend .NET?
899 A: Embracing a good technology is good. Extending technologies in
900 incompatible ways is bad for the users, so we do not plan on
901 extending the technologies.
903 If you have innovative ideas, and want to create new classes, we
904 encourage you to make those classes operate correctly well in both
907 Q: Is there any way I can develop the class libraries using Linux yet?
909 A: Yes. Some class libraries can be developed on Linux. Search for
910 Paolo's post (he lists which classes can be compiled fine now).
912 Q: Is there any way I can install a known working copy of mono in /usr,
913 and an experimental copy somewhere else, and have both copies use
914 their own libraries? (I'm still not very good at library paths in
917 A: Yes. Just use two installation prefixes.
920 <a name="portability"></a>
923 Q: Will Mono only work on Linux?
925 A: Currently, we are doing our work on Linux-based systems and
926 Windows. We do not expect many Linux-isms in the code, so it
927 should be easy to port Mono to other UNIX variants.
929 Q: What about Mono on non Linux-based systems?
931 A: Our main intention at Ximian is to be able to develop GNOME
932 applications with Mono, but if you are interested in providing a
933 port of the Winforms classes to other platforms (frame buffer or
934 MacOS X for example), we would gladly integrate them, as long
935 they are under an open source license.
937 Q: What operating systems/CPUs do you support
939 A: Mono currently runs on Linux, Windows, Solaris and FreeBSD.
940 There is a JIT engine available for x86 processors that can
941 generate code and optimizations tailored for a particular CPU.
943 Interpreters exist for the SPARC, PowerPC and StrongARM CPUs.
945 Q: Does Mono run on Windows?
947 A: Yes. You can get pre-compiled
948 binaries from <a href="http://www.go-mono.com/download.html">http://www.go-mono.com/download.html</a>
950 Q: Does Mono run on Linux?
952 A: Yes. You can get pre-compiled
953 binaries from <a href="http://www.go-mono.com/download.html">http://www.go-mono.com/download.html</a>
955 Q: Will I require Cygwin to run mono?
957 A: No. Cygwin is only required to build Mono.
959 Q: Will Mono depend on GNOME?
961 A: It will depend only if you are using a particular assembly (for
962 example, for doing GUI applications). If you are just interested
963 in Mono for implementing a `Hello World Enterprise P2P Web
964 Service', you will not need any GNOME components.
966 Q: Is anyone working on porting Mono to IA-64?
968 A: Nobody is working on such port.
970 Q: If I were about to start a Mono port to IA-64,would the same lburg code
971 generator work for IA-64 also? or anything else need to be used for code
972 generation(as the processor architecture is totally different from IA32)
974 A: The lburg approach can be use for any processor architecture. But you might
975 think in another better approach.
977 Q: Do you plan to port Rhino to C#?.
979 A: Eto Demerzal has started a Rhino port to C#.
981 Q: Has anyone succeeded in building a Mac version of the C# environment.
982 If so can you explain how?
984 A: You could try to check with the Darwin people, or the Fink people.
985 Mono/C# is self hosting on Linux/PPC which is the hard part, so it
986 should be relatively simple to get it to work on MacOS
989 ** Reusing Existing Code
991 Q: What projects will you reuse or build upon?
993 A: We want to get Mono in the hands of programmers soon. We are
994 interested in reusing existing open source software.
996 Q: What about Intel's research JIT framework, ORP?
998 A: At this time, we are investigating whether we can use elements of
999 ORP for Mono. ORP is a research JIT engine that has a clearly
1000 defined API that splits the JIT from the GC system and the actual
1001 byte code implementation.
1003 We are using some pieces of ORP (Their code generation interface)
1004 and we use it as a source of inspiration for optimizations. Paolo
1005 and Dietmar consider ORP as being one of the best JIT engines out
1006 there (and their research work and papers are very useful if you are
1007 interested in JIT technology).
1009 Q: What about using GNU Lightning?
1011 A: We are not using GNU Lightning. Our JIT is using an instruction
1012 selector based on tree-pattern matching, and a code generation
1013 interface that is very tied to the current architecture.
1015 Q: Will I be able to use Microsoft SQL Server 2000 or will I need to switch
1016 to a specific Open Source Database. Will I need to recode?
1018 A: There should not be any need to recode.
1020 Q: What do I need to watch out for when programming in VB.NET so that I'm
1021 sure to be able to run those apps on Linux?
1023 A: Not making any PInvoke or DLL calls should and not using anything in
1024 the Microsoft.* namespaces should suffice. Also do not use any
1025 Methods/Classes marked as "This type/method supports the .NET Framework
1026 infrastructure and is not intended to be used directly from your code."
1027 even if you know what these classes/methods do.
1029 Q: Will built-in reporting be supported for crystal reports? This is a
1030 heavily used part of our system.
1032 A: Probably not. Crystal Reports are propriety. Someone may try to emulate
1033 the behavior, but no-one has yet volunteered.
1035 Q: Who about writing to the registry? As I understand it, Linux does not have
1036 a counterpart to the registry. Should I avoid relying on that feature?
1038 A: Try to avoid it. Although there would be a emulation for registry in
1039 Mono too. GNOME does have a registry like mechanism for configuration. But
1040 Even if gnome has a configuration system similar to the registry, the keys
1041 will not be equal, so you will probably end up having to do some runtime
1042 detection, and depending on this load an assembly that has your
1043 platform-specific hacks.
1045 Q: System.Data.SqlClient with FreeTDS, will you port parts of these to C# and
1048 A: if their license is compatible with mono's, yes, we'd think about porting
1049 them. If not, we'll continue with the plan of using FreeTDS.
1054 Q: Are you working on a GCC front-end to C#? A GCC back-end that will
1055 generate CIL images? What about making a front-end to GCC that
1056 takes CIL images and generates native code?
1058 A: We are currently seeking volunteers for those projects.
1059 Visit the <a href="contributing.html">contributing</a> section if
1062 Q: But would this work around the GPL in the GCC compiler and allow
1063 people to work on non-free front-ends?
1065 A: People can already do this by targeting the JVM byte codes (there
1066 are about 130 compilers for various languages that target the JVM).
1068 Q: Why are you writing a JIT engine instead of a front-end to GCC?
1070 A: We want the JIT engine and runtime engine because they will be able
1071 to execute CIL executables generated on Windows, and so no recompilation
1074 <a name="performance"></a>
1077 Q: How fast will Mono be?
1079 A: We can not predict the future, but a conservative estimate is that
1080 it would be at least `as fast as other JIT engines'.
1082 We would like to ship various JIT engines with Mono, just like
1083 Microsoft has done with their .NET development platform. We could
1084 provide a faster, JIT for fast load times but lower performance,
1085 and an and an optimizing JIT that would be slower at generating
1086 code but produce more optimal output.
1088 The CIL has some advantages over the Java byte code: it is really
1089 an intermediate representation and there are a number of
1090 restrictions on how you can emit CIL code that simplify creating
1093 For example, on the CIL, the stack is not really an abstraction
1094 available for the code generator to use at will. Rather, it is a
1095 way of creating a postfix representation of the parsed tree. At
1096 any given call point or return point, the contents of the stack are
1097 expected to contain the same object types independently of how the
1098 instruction was reached.
1100 <a name="licensing"></a>
1103 Q: Will I be able to write proprietary applications that run with
1106 A: Yes. The licensing scheme is planned to allow proprietary
1107 developers to write applications with Mono.
1109 Q: What license or licenses are you using for the Mono Project?
1111 A: The C# Compiler is released under the terms of the <a
1112 href="http://www.opensource.org/licenses/gpl-license.html">GNU GPL</a>. The runtime
1113 libraries are under the <a
1114 href="http://www.opensource.org/licenses/lgpl-license.html">GNU
1115 Library GPL</a>. And the class libraries are released
1116 under the terms of the <a
1117 href="http://www.opensource.org/licenses/mit-license.html">MIT X11</a>
1120 The Mono runtime and the Mono C# Compiler are also available under
1121 a proprietary license for those who can not use the LGPL and the
1124 For licensing details, contact <a
1125 href="mailto:mono-licensing@ximian.com">mono-licensing@ximian.com</a>
1128 Q: I would like to contribute code to Mono under a particular
1129 license. What licenses will you accept?
1131 A: We will have to evaluate the licenses for compatibility first,
1132 but as a general rule, we will accept the code under the same
1133 terms of the "container" module.
1135 <a name="patents"></a>
1138 Q: Could patents be used to completely disable Mono (either submarine
1139 patents filed now, or changes made by Microsoft specifically to
1140 create patent problems)?
1142 A: No. First, its basic functional capabilities have pre-existed too
1143 long to be held up by patents. The basic components of Mono are
1144 technologically equivalent to Sun's Java technology, which has been
1147 Mono will also implement multi-language and
1148 multi-architecture support, but there are previous technologies
1149 such as UCSD p-code and ANDF that also support multiple languages
1150 using a common intermediate language. The libraries are similar
1151 to other language's libraries, so again, they're too similar to
1152 be patentable in large measure.
1154 However, if Microsoft does patent some technology, then our plan is
1155 to either (1) work around it, (2) chop out patented pieces, (3)
1156 find prior art that would render the patent useless.
1158 Not providing a patented capability would weaken the
1159 interoperability, but it would still provide the free software /
1160 open source software community with good development tools, which
1161 is the primary reason for developing Mono.
1163 There is also a statement from Jim Miller at Microsoft, one of the
1164 inventors listed in the patent: <a href="https://mailserver.di.unipi.it/pipermail/dotnet-sscli/msg00218.html">here</a>.
1166 For Linux desktop use, we only need the ECMA components, and things that
1167 we have developed (like Gtk#).
1170 ** Miscellaneous Questions
1172 Q: You say that the CLI allows multiple languages to execute on the
1173 same environment. Isn't this the purpose of CORBA?
1175 A: The key difference between CORBA (and COM) and the CLI is that the
1176 CLI allows "data-level interoperability" because every
1177 language/component uses the same data layout and memory management.
1179 This means you can operate directly upon the data types that someone
1180 else provides, without having to go via their interfaces. It also
1181 means you don't have to "marshal" (convert) parameters (data
1182 layouts are the same, so you can just pass components directly) and
1183 you don't have to worry about memory management, because all
1184 languages/components share the same garbage collector and address
1185 space. This means much less copying and no need for reference
1188 Q: Will you support COM?
1190 A: The runtime will support XPCOM on Unix systems and COM on Windows.
1191 Most of the code for dynamic trampolines exists already.
1193 Q: Will Ximian offer certifications on Mono or related technologies?.
1195 A: It's possible. But there is no plan about this. So the short answer is no.
1197 Q: Are there any Boehm's GC binaries?
1199 A: Yes. You can find RPMs <a href="http://java.thn.htu.se/~toor/">here</a>, though
1200 if your distribution provides the correct packages, you should use those.
1201 The suggested version of the Boehm GC is 6.1.
1203 Q: How can I report a bug?
1205 A: The best thing is to track down the bug and provide a simple test to
1206 reproduce the bug. You can then add the bug to the
1207 <a href="http://bugzilla.ximian.com/enter_bug.cgi">bugtracking system</a>.
1209 Please provide information about what version of mono you're using
1210 and any relevant details to be able to reproduce the bug. Note that
1211 bugs reported on the mailing-list may be easily forgotten, so it's
1212 better to file them in the <a href="http://bugzilla.ximian.com/enter_bug.cgi">bug tracking system</a>.
1214 Q: Does mcs support the same command line options as the MS C#
1217 A: The Mono C# compiler now supports the same command line
1218 arguments as the Microsoft C# compiler does.
1220 Q: How about getting searchable archives on lists.ximian.com?
1222 A: You can perform a search on the mono-related mailing lists
1223 <a href="http://www.go-mono.com/mailing-lists.html">here</a>.
1225 Q: When using mono from cvs or from a snapshot, I get an error messaage
1226 saying that Mono and the runtime are out of sync. How do I fix that?
1228 A: If you use mono from cvs, you need to be prepared for changes in the
1229 runtime internals. This means that you should keep a working setup
1230 before blindling updating (a working setup may just be the last released
1231 tarball or a recent binary snapshot).
1232 Usually, compiling corlib with mcs before recompiling the C runtime does
1233 the right thing (but occasionally you may need to do it the other
1236 Q: Why are you going for a GtkHtml implementation?
1238 A: GtkHTML is just a lightweight HTML rendering engine that does not
1239 support CSS, so we need it to look decent for those of us that will
1240 be using the documentation in our day-to-day work on Linux. The
1241 Web-based interfaces lack the agility that you get from a native GUI
1242 tool to browse your documentation. Probably later on, we will write
1243 scripts and generate a full documentation set that is web-browsable,
1244 but we need a command-line and GUI tools that we can use natively on
1245 Linux when disconnected from the Web (and that has better
1246 interactions than a web page).
1248 Q: Is there a command-line tool that allows me to access .NET interactively?
1250 A: There are several but one that is free software and uses MCS is the one
1251 Dennis Lu from Rice University is working on; a REPL C# interpreter.
1253 Q: Is it possible to use Visual C++ with Mono?.
1255 A: Well, It's possible to run VC++ generated apps under Mono though.
1257 <a name="problems"></a>
1258 ** Mono Common Problems
1260 If you are having problems compiling or running Mono software
1261 or if you think that you found a bug, etc. Please visit the
1262 <a href="http://geneura.ugr.es/~jaime/deploy/mono-common-problems.html">Mono Common Problems</a> document and try there.