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="#winforms">Mono and WinForms</a><br>
6 <a href="#msft">Mono and Microsoft</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="#devel">Development Tools and Issues</a><br>
12 <a href="#java">Mono and Java</a><br>
13 <a href="#extending">Extending Mono</a><br>
14 <a href="#portability">Portability</a><br>
15 <a href="#reuse">Reusing Existing Code</a><br>
16 <a href="#gcc">Mono and GCC</a><br>
17 <a href="#performance">Performance</a><br>
18 <a href="#licensing">Licensing</a><br>
19 <a href="#patents">Patents</a><br>
20 <a href="#etc">Miscellaneous Questions</a><br>
21 <a href="#problems">Mono Common Problems</a><br>
24 href="http://www.es.gnome.org/documentacion/articulos/MONO-PUF/MONO-PUF/">spanish
25 translation</a> is also available
30 Q: What is Mono exactly?
32 A: The Mono Project is an open development initiative sponsored by
33 Ximian that is working to develop an open source, Unix
34 version of the Microsoft .NET development platform. Its objective
35 is to enable Unix developers to build and
36 deploy cross-platform .NET Applications. The project will
37 implement various technologies developed by Microsoft that have now
38 been submitted to the ECMA for standardization.
40 Q: What is the difference between Mono and the .NET Initiative?
42 A: The ".NET Initiative" is a somewhat nebulous company-wide effort by
43 Microsoft, one part of which is a cross-platform development
44 framework. Mono is an implementation of the development framework,
45 but not an implementation of anything else related to the .NET
46 Initiative, such as Passport, software-as-a-service, or
49 Q: What technologies are included in Mono?
51 A: Mono contains a number of components useful for building new
55 * A Common Language Infrastructure (CLI) virtual
56 machine that contains a class loader, Just-in-time
57 compiler, and a garbage collecting runtime.
59 * A class library that can work with any language
60 which works on the CLR.
62 * A compiler for the C# language. In the future we
63 might work on other compilers that target the Common
68 Windows has compilers that target the virtual machine from <a
69 href="http://msdn.microsoft.com/net/thirdparty/default.asp#lang">a
70 number of languages:</a> Managed C++, Java Script, Eiffel,
71 Component Pascal, APL, Cobol, Perl, Python, Scheme,
72 Smalltalk, Standard ML, Haskell, Mercury and Oberon.
74 The CLR and the Common Type System (CTS) enables applications and
75 libraries to be written in a collection of different languages that
78 This means for example that if you define a class to do algebraic
79 manipulation in C#, that class can be reused from any other
80 language that supports the CLI. You could create a class in C#,
81 subclass it in C++ and instantiate it in an Eiffel program.
83 A single object system, threading system, class libraries, and
84 garbage collection system can be shared across all these languages.
86 Q: Where can I find the specification for these technologies?
88 A: You can find the work-in-progress documentation from the T3G ECMA
91 <a href="http://www.dotnetexperts.com">http://www.dotnetexperts.com</a>
93 Q: Will you implement the .NET Framework SDK class libraries?
95 A: Yes, we will be implementing the APIs of the .NET Framework SDK
98 Q: Will you offer an ECMA-compliant set of class libraries?
100 A: Eventually we will. Our current focus is on interoperating
101 with the Microsoft SDK, but we will also offer an ECMA compliant
104 Q: What does the name "Mono" mean?
106 A: Mono is the word for `monkey' in Spanish. We like monkeys.
110 A: The JIT engine is usable on Intel x86 machines. An interpreter
111 can be used on other non-Intel x86 machines.
113 The class libraries are mature enough to run some real applications
114 (the compiler for instance, and every day more and more applications
115 are natively developed with Mono).
117 Q: When will you ship it?
119 A: Different parts of Mono will achieve usability at different stages,
120 once we are comfortable with the compiler, we will release "Mono Core",
121 which contains everything needed to develop applications with the base
122 class libraries. This should be available at some point during 2002.
124 Other higher level class libraries (ASP.NET, ADO.NET) will
125 be released when they become stable.
127 Q: What major components will you include in Mono?
129 A: Hopefully everything that Microsoft ships on their Framework
130 (ADO.NET, ASP.NET), and
131 we encourage third party developers to create reusable components that
132 work on both Mono and Windows.
134 Q: How can I contribute?
136 A: Check the <a href="contributing.html">contributing</a> section.
138 Q: Aren't you just copying someone else's work?
140 A: We are interested in providing the best tools for programmers to
141 develop applications for Free Operating Systems. We also want to help
142 provide the interoperability that will allow those systems to fit in
143 with other standards.
145 For more background, read the <a href="http://www.go-mono.com/rationale.html">Mono
146 Project white paper</a>.
149 Q: Miguel said once that Mono was being implemented in COBOL. Is that true?.
151 A: No. It was a joke.
154 <a name="ximian"></a>
156 ** The Ximian Role in the Mono Project
158 Q: Why is Ximian working on .NET?
160 A: Ximian is interested in providing the best tools for programmers to
161 develop applications for Free Operating Systems.
163 For more information, read the project <a
164 href="rationale.html">rationale</a> page.
166 Q: Will Ximian be able to take on a project of this size?
168 A: Of course not. Ximian a supporter of the Mono project, but the only way
169 to implement something of this size is for the entire free software
170 community to get involved. Visit the <a href="contributing.html">contributing</a>
171 page if you'd like to help out.
173 Q: What pieces will Ximian be working on?
175 A: We will devote most of our resources to work on the pieces which are
176 on the critical path to release a development and execution
177 environment. Once the project is at a stage where it is useful in
178 the real world, it will achieve a critical mass of developers to
181 Q: Will Ximian offer Mono commercially?
183 A: When Mono is ready to be shipped Ximian will offer a commercial
184 support and services for Mono.
186 Q: Does Ximian provide consulting services around Mono?
188 A: Yes, Ximian does provide consulting services around Mono to
189 make it suitable to your needs. Porting the runtime engine,
190 customizing it, working on specific classes or tuning the code
191 for your particular needs.
193 Q: Will you wait until Mono is finished?
195 A: Mono will ship on various stages as they mature. Some people
196 require only a subset of the technologies, those will ship first.
198 More advanced features will take more time to develop. A support
199 timeline will be available in June 2002.
204 Q: How is Mono related to GNOME?
206 A: In a number of ways. This project was born out of the need of
207 providing improved tools for the GNOME community, and will use
208 existing components that have been developed for GNOME when they
209 are available. For example, we plan to use Gtk+ and Libart to
210 implement Winforms and the Drawing2D API and are considering
213 Q: Has the GNOME Foundation or the GNOME team adopted Mono?
215 A: Mono is too new to be adopted by those groups. We hope that the
216 tools that we will provide will be adopted by free software
217 programmers including the GNOME Foundation members and the GNOME
220 Q: Should GNOME programmers switch over to Mono now?
222 A: It is still far to early for discussions of "switching over." No
223 pieces of Mono will be ready within the next six months, and a
224 complete implementation is roughly one year away.
226 We encourage GNOME developers to continue using the existing tools,
227 libraries and components. Improvements made to GNOME will have an
228 impact on Mono, as they would be the "backend" for various classes.
230 Q: Will Mono include compatibility with Bonobo components? What is the
231 relationship between Mono and Bonobo?
233 A: Yes, we will provide a set of classes for implementing and using
234 Bonobo components from within Mono. Mono should allow you to write
235 Bonobo components more easily, just like .NET on Windows allows you
236 to export .NET components to COM.
238 Q: Does Mono depend on GNOME?
240 A: No, Mono does not depend on GNOME. We use a few packages produced by
241 the GNOME team like the `glib' library.
243 Q: But will I be able to build GNOME applications?
245 A: Yes, we will enable people to write GNOME applications using Mono.
247 Q: Do you have C# bindings for GNOME?.
249 A: Yes, we currently bind libgnome, libgnomecanvas, and libgnomeui --
250 although I dare say I have no idea how functional the bindings are
251 outside of what I tested in the sample app. I imagine other libraries
252 under the GNOME framework will be added on an as-needed (and as-requested)
253 basis...although a truly good bonobo binding will have to wait on the CORBA
254 remoting support which has been started recently.
259 Q: Will Mono enable GUI applications to be authored?
261 A: Yes, you will be able to build GUI applications. Indeed, that is our
262 main focus. We will provide both the Windows.Forms API and the Gtk# API.
264 Q: What is the difference between Gtk# and System.Windows.Forms?
266 A: Gtk# is a set of bindings for the Gtk+ toolkit for C# (and other
267 CIL-enabled languages). System.Windows.Forms is an API defined
268 by Microsoft to build GUI applications.
270 Q: Will I be able to run my smart clients on systems powered by Mono?
272 A: As long as your applications are 100% .NET and do not make use
273 of P/Invoke to call Win32 functions, your smart client applications
274 will run on Mono platforms.
276 Q: Where can I learn mora about Gtk#?
278 A: The following <a href="http://gtk-sharp.sourceforge.net>link</a> sends you to the page of the project.
280 Q: What can I do with Gtk#?.
282 A: Gtk# is becoming very usable and you can create applications and
283 applets like those you see in a GNOME desktop environment. It's
284 easy to install so it's worth a try.
286 Q: How can I compile my HelloWorld.cs which uses Gtk#?.
288 A: Try: mcs --unsafe -o HelloWorld.exe -r glib-sharp -r pango-sharp -r
289 atk-sharp -r gdk-sharp -r gtk-sharp -r gdk-imaging-sharp
292 Q: Is there any way how to connect DataAdapter to some GTK# controls?
294 A: There is a sample file called `DbClient' in gtk-sharp/samples that you
295 might to look at. It is a sample program in Gtk# that adds/updates/deletes
296 information on a Postgress database. When we have the new table/tree widgets,
297 I am sure someone would write an adapter for System.Data (in Gtk2 the
298 tree/list widgets are written using a view/model, so you only need to write
299 a model that maps to the database). You can have a look at
300 gtk-sharp/sample/DbClient, where there is a GTK# application that uses
301 System.Data. It does not use DataAdapter, but DataReader though.
303 <a name="winforms"></a>
306 Q: Can you tell me why aren't you implementing WinForms?.
308 A: (This is based in an original mail to mono-list written by Miguel de
309 Icaza. You should read it for completion, but the core part is here).
311 First, Windows.Forms is packed with quirks and is not that great of a
312 toolkit in the first place. Up to the point of the unconfirmed rumor
313 that Microsoft is working on a replacement for it.
315 Once the runtime is done, we will very likely start contributing to
316 the Gtk# project ourselves, and we will likely start doing feasibility
317 work on getting Mono used by Gnome developers: full gnome apps and
318 extending existing applications.
320 Those interested in hacking on Windows.Forms are welcome to do so,
321 but Ximian will not likely look at it in the near future; if there is
322 enough demand, or I can be convinced that Windows.Forms is useful for
323 something Ximian might re-evaluate our resource allocation for this
326 By doing native ports, we could use the same API on all those systems.
327 Also, Gtk is mature enough, we know this because we have built an entire
328 desktop (and all sorts of very window system-specific hacks), and we
329 have built a bunch of productivity applications with it.
333 Someone mentioned VCL. The only problem with the VCL is that it can
334 only be used for GPL applications (or I guess you could license it from
335 Borland for your app), and would have to be ported from Delphi to C#
336 (or someone would have to write a CIL compiler for it).
338 Q: What about doing something like the eclipse project (www.eclipse.org)?
340 A: The Eclipse toolkit is not a general purpose toolkit. It will require a
341 lot of work before it is such a thing. It is a toolkit used to
342 implement a development environment.
346 ** Mono and Microsoft
348 Q: Is Microsoft helping Ximian with this project?
350 A: No. Ximian CTO Miguel de Icaza had a friendly conversation with
351 Microsoft software architect David Stutz, but that's about the
352 extent of the contact. Microsoft is interested in other
353 implementations of .NET and are willing to help make the ECMA spec
354 more accurate for this purpose.
356 Ximian representatives have also spoken with Sam Ruby at the ECMA
357 TG3 committee to discuss the same issues.
359 Q: Is Microsoft or Corel paying Ximian to do this?
363 Q: Do you fear that Microsoft will change the spec and render Mono
366 A: No. Microsoft proved with the CLI and the C# language that it was
367 possible to create a powerful foundation for many languages to
368 interoperate. We will always have that.
370 Even if changes happened in the platform which were undocumented,
371 the existing platform would a value on its own.
373 Q: Are you writing Mono from the ECMA specs?
375 A: Yes, we are writing them from the ECMA specs and the published
376 materials in print about .NET.
378 Q: If my applications use Mono, will I have to pay a service fee?
380 A: No. Mono is not related to Microsoft's initiative of
381 software-as-a-service.
383 Q: Is the Mono Project is related to the Microsoft Hailstorm effort? Is
384 Ximian endorsing Hailstorm?
386 A: No. The Mono Project is focused on providing a compatible set of
387 tools for the Microsoft .NET development platform. It does not
388 address, require, or otherwise endorse the MS Passport-based
389 Hailstorm single sign-on system that is part of Windows XP and
392 Q: Will Mono or .NET applications depend on Microsoft Passport?
394 A: No. MS Passport is unrelated to running .NET compatible applications
395 produced with the Mono tools. The only thing you will need is a
396 just-in-time compiler (JIT).
398 Q: What is a 100% .NET application?
400 A: A `100% .NET application' is one that only uses the APIs defined
401 under the System namespace and does not use PInvoke. These
402 applications would in theory run unmodified on Windows, Linux,
403 HP-UX, Solaris, MacOS X and others.
405 Q: If Microsoft will release a port of their .NET platform under the
406 `Shared Source' license, why should I bother with anything else?
408 A: The Shared Source implementation will be expensive and its uses
409 will be tightly restricted, especially for commercial use. We are
410 working towards an implementation that will grant a number of
411 important rights to recipients: use for any purpose,
412 redistribution, modification, and redistribution of modifications.
414 This is what we call <a
415 href="http://www.gnu.org/philosophy/free-sw.html">Free Software</a>
417 Q: Is Mono a free implementation of Passport?
419 A: No. Mono is just a runtime, a compiler and a set of class
422 Q: Will the System.Web.Security.PassportIdentity class mean
423 that my software will depend on Passport?
425 A: No. Applications may use that API to contact a Passport site, but
426 are not required to do so.
428 As long as your application does not use Passport, you will not
431 Q: Will Mono running on Linux make Passport available for Linux?
433 A: No. However, the Passport toolkit for Linux-based web servers is
434 available from Microsoft.
436 Q: Will Mono allow me to run Microsoft Office on Linux?
438 A: No, it will not. Microsoft Office is a Windows application. To
439 learn more about running Windows applications on Intel Unix systems
440 refer to <a href="http://www.winehq.com">the Wine Project</a>.
442 Q: Will I be able to compile a Microsoft VB.NET application and execute
443 the resultant MSIL file under MONO on Linux without converting to C#
446 A: Once we have a complete VisualBasic runtime, yes.
448 Q: Can mono run the WebMatrix ?
450 A: No. That requires winforms (we don't have).
452 Q: Does mono have something like Passport ? (ie PassportIdentity class,somewhere
453 in System.Web ?) . Will mono have a server side Passport/Similar framework
454 for XSP as well as client classes ?
456 A: Not yet, but the client side API for authentication is not the problem.
457 We will likely have a lot of other authentication APIs, like the Liberty
458 Aliance APIs. The problem is people on the web provider end that might use
459 this for authentication.
461 <a name="pnpproject"></a>
462 ** Mono and Portable.NET
464 Q: What are the differences between Mono and Portable.NET?
466 A: Most of Mono is being written using C#, with only
467 a few parts written in C (The JIT engine, the runtime, the
468 interfaces to the garbage collection system).
470 It is easier to describe what is unique about Mono:
472 <li> A self-hosting C# compiler written in C#, which is clean, easy
475 <li> A multi-platform runtime engine: both a JIT engine and an
476 interpreter exist. The JIT engine runs currently on x86
477 systems, while the interpreter works on Sparc, StrongARM and
480 <li> Supports Linux, Windows and Solaris at this point.
482 <li> The JIT engine is written using a portable instruction
483 selector which not only generates good code (we are told
484 that we are faster than Rotor, but it is hard to tell) but
485 is also the foundation to retarget the JIT engine to other
488 The system employed is described in various compiler
489 books and it is very similar to what is described in the
490 book that covers LCC, the Ansi C retargetable C compiler.
492 <li> The JIT engine supports inlining, constant folding and propagation,
494 <li> Full support for remoting in the runtime, but the class
495 libraries are still behind.
497 <li> The C# compiler, the JIT engine and the class libraries are
498 mature enough that the whole system is self-hosting, ie, that
499 it can be fully developed with itself at this point.
501 <li> We are not yet done, and there is a lot of work left to be
504 <li> We have a great community of developers, without which Mono
505 would not be possible.
507 <li> We will provide an ahead of time compilation mode in the
511 <a name="webservices"></a>
514 Q: How is Mono related to Web Services?
516 A: Mono is only related to Web Services in that it will implement the
517 same set of classes that have been authored in the .NET Framework
518 to simplify and streamline the process of building Web Services.
520 But most importantly, Mono is an Open Source implementation of the
523 Q: Can I author Web Services with Mono?
525 A: You will be able to write Web Services on .NET that run on Mono and
528 Q: If Mono implements the SDK classes, will I be able to write and
529 execute .NET Web Services with it?
531 A: Yes. When the project is finished, you will be able to use the
532 same technologies that are available through the .NET Framework SDK
533 on Windows to write Web Services.
535 Q: What about Soup? Can I use Soup without Mono?
537 A: Soup is a library for GNOME applications to create SOAP servers and
538 SOAP clients, and can be used without Mono. You can browse the
539 source code for soup using <a
540 href="http://cvs.gnome.org/bonsai">GNOME's Bonsai</a>.
544 A: Yes. The CLI contains enough information about a class that
545 exposing it to other RPC systems (like CORBA) is really simple, and
546 does not even require support from an object.
548 We will be implementing CORBA interoperation as an extension to the
549 Mono classes so that we can integrate with Bonobo, just like
550 Microsoft provides COM interoperation classes and support
553 Q: Can I serialize my objects to other things other than XML?
555 A: Yes, although the serializing tools have not yet been planned, and
556 you would probably have to implement them yourself.
558 Q: Will Mono use ORBit?
560 A: No. Mono will be using a new implementation of CORBA that isn't still started.
563 ** Development Tools and Issues
565 Q: Will it be possible to use the CLI features without using bytecodes
568 A: Yes. The CLI engine will be made available as a shared library.
569 The garbage collection engine, the threading abstraction, the
570 object system, the dynamic type code system and the JIT will be
571 available for C developers to integreate with their applications if
574 Q: Will you have new development tools?
576 A: With any luck, Free Software enthusiasts will contribute tools to
577 improve the developer environment. These tools could be developed
578 initially using the Microsoft implementation of the CLI and then
579 executed later with Mono.
581 Q: What kind of rules make the Common Intermediate Language useful for
584 A: The main rule is that the stack in the CLI is not a general purpose
585 stack. You are not allowed to use it for other purposes than
586 computing values and passing arguments to functions or return
589 At any given call or return instruction, the types on the stack
590 have to be the same independently of the flow of execution of your
593 Q: Is it true that the CIL is ideal for JITing and not efficient for
596 A: The CIL is better suited to be JITed than JVM byte codes, but you
597 can interpret them as trivially as you can interpret JVM byte
600 Q: Isn't it a little bit confusing to have the name of "XSP" (the same
601 as in the Apache Project) for the ASP.NET support in Mono?.
603 A: In Mono, xsp is just the name of the C# code generator for ASP.NET
604 pages. In the Apache Project, it is a term for the "eXtensible Server
605 Pages" technology so as they are very different things, they don't
608 Q: What about using something like Jabber instead of the System.Messaging
611 A: In short, MSMQ is not something like Jabber, but asynchronous messaging
612 through queues. Usefull queues do more than serialize messages, they are
613 also platform bridges.
615 Q: Are you supporting XMLDocument and relatives?.
617 A: Currently, we aren't implementing them yet. It would require updates to
618 most of the XmlNode derivatives so it's not a trivial task. We are
619 currently focusing on getting XPath support working.
621 Q: Is there any plan to develop an aspx server for Mono?.
623 A: The webserver turned out to be very simple compared to the rest of the
624 work. Gonzalo has got the page generator mostly done (a module called
625 xsp, who has nothing to do with the XSP term used in the Apache Project).
626 Patrik has done a lot of the work to get the ProcessRequest to work.
627 You can try to help in the final touches to the System.Web classes and
628 writing regression tests for the widgets we have.
630 Q: Is there any way I can develop the class libraries using linux yet?
632 A: Yes. Some class libraries can be developed on Linux. Search for
633 Paolo's post (he lists which classes can be compiled fine now).
635 Q: Is there any way I can install a known working copy of mono in /usr,
636 and an experimental copy somewhere else, and have both copies use
637 their own libraries? (I'm still not very good at library paths in
640 A: Yes. Just use two installation prefixes.
642 Q: How should I write tests or a tests suite?
644 A: If you do a test suite for C#, you might want to keep it
645 independent of the Mono C# compiler, so that other compiler
646 implementations can later use it.
648 Q: Is the current stage the implementation of mono_create_trampoline
649 function? Hence the sparc-codegen.h is reasonably complete? Is
650 mono/arch/x86/* the best reference material for this stuff?
652 A: sparc-codegen.h is basically complete. We may want to add some
653 convenience macros along the way, but it has all the stuff you need.
654 And yes, or, the ppc/ dir, since the ppc call convention is more similar
655 to the sparc one than the x86 one. The current issues with the sparc
657 1) it needs to handle overflowing the out registers (the additional
658 arguments need to be put on the stack)
659 2) it needs to flush the icache where the generated code is stored
660 3) it needs to implement mono_create_method_pointer to get delegates
662 4) it needs a couple of updates (mono_method_pointer_get is no longer
665 Q: Would it be too terrible to have another corlib signed as mscorlib?
667 A: We rename corlib to mscorlib also when saving the PE files, in fact,
668 the runtime can execute program created by mono just fine.
670 Q: How do I build corlib under Linux?
672 A: You can build your own (see the web site on how to get the mcs
673 project from cvs), but in order to build them using mcs you need a
674 set of working class libraries. After building the runtime (using
675 mono-build.sh) get them from the nightly build and put them (and
676 mcs.exe) in your mono/install/lib directory. Then you should be able
677 to do: cd mcs, then: make -f makefile.gnu, then: cp mcs/mcs.exe
678 class/lib/*.dll ../install/lib Also, you should know that you can
679 either get your dose of DLLs from MonoCharge, or from
680 http://primates.ximian.com/~miguel/runtime. MonoCharge is updated
681 automatically, while the later is only updated when Miguel is around
682 Once you have the DLLs, you can use `make -f makefile.gnu' as described
685 Q: Is there a relatively straightforward way to repeat the steps taken
686 by Paolo to get Mono completely self-hosted on linux?
688 A: To build the compiler and class libraries in Linux, run:
689 <ul><li>make -f makefile.gnu. To install them, run: </li>
690 <li>make -f makefile.gnu install</li>
691 <li>You can also specify a prefix:</li>
692 <li>make -f makefile.gnu install prefix=/opt</li>
694 If you want to produce and distribute a monocharge tarball, run:
695 make -f makefile.gnu dist
696 Of course you have to run these in the top level mcs directory.
698 Q: Is it possible to build a C# file to some sort of intermediate format which
699 can linked into a final module, like the traditional .c -> .o -> .so path?
701 A: You could do: mcs /target:module file1.cs, mcs /target:module file2.cs,
702 mcs /target:exe file1.dll file2.dll /out:mybin.exe
704 Q: Is there any plans for implementing remoting in the near future?, When will
705 work in System.Runtime.Remoting.dll start?
707 A: The remoting infrastructure is in place. Some of the channels and
710 Q: I'm wondering if there are any plans to start using nant to build the
711 class lib + test lib. i think that every project neeed/should use an
712 automated build process and nant + a couple of tools enables this. is
713 the problem that the compiler can't run nant yet?
715 A: Maybe well be doing some sort of automated build process + testing when
721 Q: Is Mono supporting ASP.NET?
723 A: Yes. The development of the support for ASP.NET comes in various stages,
724 here is what Gonzalo has been working on: 1. The Parser. 2. Getting the
725 parser to generate output compatible with ASP.NET. 3. Running the sample
726 output with the real Microsoft runtime but using our generated page. 4.
727 Running the sample with our classes with the .NET runtime. 5. Running
728 our sample code with our classes with our runtime. This is the process
729 we are following. Currently Gonzalo has reached point 5.
731 Q: Do I need install cygwin to work on ASP.NET in mono or Linux is enough since
732 it is self host right now.
736 Q: Any plan to make ASP.NET in mono works with Apache in linux?.
738 A: Yes, we have plans to do so, but we need to wait for Patrik's patches to
739 HttpRuntime. Once that is there, writing a mod_mono should be trivial
740 (look at mono/samples/embed for a sample embedded application).
745 Q: What is the status of ADO.NET support?. Could I start migrating
746 applications from MS.NET to Mono?.
748 A: You could start right now using the ADO.NET support in mono, of course,
749 if you want to help filling the missing gaps while you develop your app
750 :-) Well, what I mean is that we're not that far to having full ADO.NET
751 support in Mono, and we've got a lot of working things, so if we could
752 get more help, we'd finish it really soon :-)
754 Q: In developing the data architecture for the application are there and
755 objects I should stay away from in order to insure the smoothest possible
756 transition (minimum code rewrite) to Mono's ADO.NET implementation? (For
757 example, strongly typed datasets versus untyped datasets, etc...)
759 A: we are implementing all the classes in Microsoft .NET's System.Data, so
760 you can be sure that things will work the same in Mono as with the MS's
761 implementation. We'll maybe provide extra classes to fix some things
762 we've found missing while developing ADO.NET in Mono, but if you keep
763 using the MS's System.Data classes, things will work out of the box with
764 no changes (or at least that's the plan :-)
769 Q: Why don't you use Java? After all, there are many languages that
772 A: You can get very good tools for doing Java development on free
773 systems right now. <a href="http://www.redhat.com">Red Hat</a> has
774 contributed a <a href="http://gcc.gnu.org">GCC</a> <a
775 href="http://gcc.gnu.org/java">frontend for Java</a> that can take
776 Java sources or Java byte codes and generate native executables; <a
777 href="http://www.transvirtual.com">Transvirtual</a> has implemented
778 <a href="http://www.kaffe.org">Kaffe</a> a JIT engine for Java;
779 Intel also has a Java VM called <a
780 href="http://www.intel.com/research/mrl/orp">ORP</a>.
782 The JVM is not designed to be a general purpose virtual machine.
783 The Common Intermediate Language (CIL), on the other hand, is
784 designed to be a target for a
785 wide variety of programming languages, and has a set of rules
786 designed to be optimal for JITers.
788 Q: Could Java target the CLI?
790 A: Yes, Java could target the CLI. We have details on a <a
791 href="ideas.html#guavac">project</a> that someone could take on to
794 Microsoft has an implemenation of the Java language called J# that
795 can target the CIL execution engine.
797 Q: Is it possible to write a JVM byte code to CIL convertor?
799 A: Yes, it is possible. Here are a few starting point:
802 * A byte code representation is really a flattened forest of
803 trees. Look at the Mono JIT engine to see how we compute
804 the basic blocks (this is used to figure out the "trees").
806 The forest is just an array of trees.
808 Indeed, run the JIT engine with -d (mono -d prog.exe) and
809 you will see how these trees look like.
811 You will have to do something similar for Java.
813 * Each "forest of trees" has a meaning. This meaning can now
814 be translated into the equivalent "meaning" in CLR-land.
817 Q: Could mono become a hybrid cil/java platform?
819 A: No. It is quite far from the philosophy of the project. The idea of Mono
820 is, to have only _one_ VM, on which all can run. And if there existing a
821 binary-converter from Java-.class to IL and if there existing something
822 like J-Sharp on Mono, you can write programs in Java, which than can run
823 on Mono. You do not need two bindings (like your example: GTK-Sharp _and_
824 Java-Gnome). You need only _one_ of it (GTK-Sharp). Thats the idea of Mono.
825 An other point is, that there are no people, who use OpenSource-JVMs. They
826 all prefer Suns original. But for Unix there don't exist a .NET-Framework.
827 So it is possible, that in the future Mono is the standard .NET for unixes.
829 Q: Do you plan to implement a Javascript compiler?
831 A: Yes. Eto Demerzal has started a Rhino port to C#.
832 After this is completed, we will begin developing
833 the Javascript compiler.
835 <a name="extending"></a>
838 Q: Would you allow other classes other than those in the
841 A: Yes. The Microsoft class collection is very big, but it is by no
842 means complete. It would be nice to have a port of `Camel' (the
843 Mail API used by Evolution inspired by Java Mail) for Mono
846 You might also want to look into implementing CORBA for Mono. Not
847 only because it would be useful, but because it sounds like a fun
848 thing to do, given the fact that the CLI is such a type rich
851 For more information on extending Mono, see our <a
852 href="ideas.html">ideas</a> page.
854 Q: Do you plan to Embrace and Extend .NET?
856 A: Embracing a good technology is good. Extending technologies in
857 incompatible ways is bad for the users, so we do not plan on
858 extending the technologies.
860 If you have innovative ideas, and want to create new classes, we
861 encourage you to make those classes operate correctly well in both
864 Q: Is there any way I can develop the class libraries using linux yet?
866 A: Yes. Some class libraries can be developed on Linux. Search for
867 Paolo's post (he lists which classes can be compiled fine now).
869 Q: Is there any way I can install a known working copy of mono in /usr,
870 and an experimental copy somewhere else, and have both copies use
871 their own libraries? (I'm still not very good at library paths in
874 A: Yes. Just use two installation prefixes.
877 <a name="portability"></a>
880 Q: Will Mono only work on Linux?
882 A: Currently, we are doing our work on Linux-based systems and
883 Windows. We do not expect many Linux-isms in the code, so it
884 should be easy to port Mono to other UNIX variants.
886 Q: What about Mono on non Linux-based systems?
888 A: Our main intention at Ximian is to be able to develop GNOME
889 applications with Mono, but if you are interested in providing a
890 port of the Winform classes to other platforms (frame buffer or
891 MacOS X for example), we would gladly integrate them, as long
892 they are under an open source license.
894 Q: What operating systems/CPUs do you support
896 A: Mono currently runs on Linux, Windows, Solaris and FreeBSD.
897 There is a JIT engine available for x86 processors that can
898 generate code and optimizations tailored for a particular CPU.
900 Interpreters exist for the SPARC, PowerPC and StrongARM cpus.
902 Q: Does Mono run on Windows?
904 A: Yes. The Compiler and the runtime both run on Windows.
906 Q: When will mono and mcs compile on Linux?.
908 A: That happend a long time ago. Know you can download and compile
909 them or even install them from already made binary packages for
910 Windows and for Linux (RPM/DEB).
912 Q: Will I require Cygwin to run mono?
914 A: No. While you'll need it to compile it, it runs without cygwin and does not even require cygwin1.dll
916 Q: Will Mono depend on GNOME?
918 A: It will depend only if you are using a particular assembly (for
919 example, for doing GUI applications). If you are just interested
920 in Mono for implementing a `Hello World Enterprise P2P Web
921 Service', you will not need any GNOME components.
923 Q: Is anyone working on porting Mono to IA-64?
925 A: Nobody is working on such port.
927 Q: If I were about to start a Mono port to IA-64,would the same lburg code
928 generator work for IA-64 also? or anything else need to be used for code
929 generation(as the processor architecture is totally different from IA32)
931 A: The lburg approach can be use for any processor architecture. But you might
932 think in another better approach.
934 Q: Do you plan to port Rhino to C#?.
936 A: Eto Demerzal has started a Rhino port to C#.
938 Q: Has anyone succeeded in building a Mac version of the C# environment.
939 If so can you explain how?
941 A: You could try to check with the Darwin people, or the Fink people.
942 Mono/C# is self hosting on Linux/PPC which is the hard part, so it
943 should be relatively simple to get it to work on macos
946 ** Reusing Existing Code
948 Q: What projects will you reuse or build upon?
950 A: We want to get Mono in the hands of programmers soon. We are
951 interested in reusing existing open source software.
953 Q: What about Intel's research JIT framework, ORP?
955 A: At this time, we are investigating whether we can use elements of
956 ORP for Mono. ORP is a research JIT engine that has a clearly
957 defined API that splits the JIT from the GC system and the actual
958 byte code implementation.
960 We are using some pieces of ORP (Their code generation interface)
961 and we use it as a source of inspiration for optimizations. Paolo
962 and Dietmar consider ORP as being one of the best JIT engines out
963 there (and their research work and papers are very useful if you are
964 interested in JIT technology).
966 Q: What about using GNU Lightning?
968 A: We are not using GNU Lightning. Our JIT is using an instruction
969 selector based on tree-pattern matching, and a code generation
970 interface that is very tied to the current architecture.
972 Q: Will I be able to use Microsoft SQL Server 2000 or will I need to switch
973 to a specific Open Source Database. Will I need to recode?
975 A: There should not be any need to recode.
977 Q: What do I need to watch out for when programming in VB.NET so that I'm
978 sure to be able to run those apps on Linux?
980 A: Not making any PInvoke or DLL calls should and not using anything in
981 the Microsoft.* namespaces should suffice. Also do not use any
982 Methods/Classes marked as "This type/method supports the .NET Framework
983 infrastructure and is not intended to be used directly from your code."
984 even if you know what these classes/methods do.
986 Q: Will built-in reporting be supported for crystal reports? This is a
987 heavily used part of our system.
989 A: Probably not. Crystal Reports are propriety. Someone may try to emulate
990 the behaviour, but no-one has yet volunteered.
992 Q: Who about writing to the registry? As I understand it, Linux does not have
993 a counterpart to the registry. Should I avoid relying on that feature?
995 A: Try to avoid it. Although there would be a emulation for registry in
996 Mono too. GNOME does have a registry like mechanism for configuration. But
997 Even if gnome has a configuration system similar to the registry, the keys
998 will not be equal, so you will probably end up having to do some runtime
999 detection, and depending on this load an assembly that has your
1000 platform-specific hacks.
1002 Q: System.Data.SqlClient with FreeTDS, will you port parts of these to C# and
1005 A: if their license is compatible with mono's, yes, we'd think about porting
1006 them. If not, we'll continue with the plan of using FreeTDS.
1011 Q: Are you working on a GCC front-end to C#? A GCC backend that will
1012 generate CIL images? What about making a front-end to GCC that
1013 takes CIL images and generates native code?
1015 A: We are currently seeking volunteers for those projects.
1016 Visit the <a href="contributing.html">contributing</a> section if
1019 Q: But would this work around the GPL in the GCC compiler and allow
1020 people to work on non-free front-ends?
1022 A: People can already do this by targeting the JVM byte codes (there
1023 are about 130 compilers for various languages that target the JVM).
1025 Q: Why are you writing a JIT engine instead of a front-end to GCC?
1027 A: We want the JIT engine and runtime engine because they will be able
1028 to execute CIL executables generated on Windows, and so no recompilation
1031 <a name="performance"></a>
1034 Q: How fast will Mono be?
1036 A: We can not predict the future, but a conservative estimate is that
1037 it would be at least `as fast as other JIT engines'.
1039 We would like to ship various JIT engines with Mono, just like
1040 Microsoft has done with their .NET development platform. We could
1041 provide a faster, JIT for fast load times but lower performance,
1042 and an and an optimizing JIT that would be slower at generating
1043 code but produce more optimal output.
1045 The CIL has some advantages over the Java byte code: it is really
1046 an intermediate representation and there are a number of
1047 restrictions on how you can emit CIL code that simplify creating
1050 For example, on the CIL, the stack is not really an abstraction
1051 available for the code generator to use at will. Rather, it is a
1052 way of creating a postfix representation of the parsed tree. At
1053 any given call point or return point, the contents of the stack are
1054 expected to contain the same object types independently of how the
1055 instruction was reached.
1057 <a name="licensing"></a>
1060 Q: Will I be able to write proprietary applications that run with
1063 A: Yes. The licensing scheme is planned to allow proprietary
1064 developers to write applications with Mono.
1066 Q: What license or licenses are you using for the Mono Project?
1068 A: The C# Compiler is released under the terms of the <a
1069 href="http://www.opensource.org/licenses/gpl-license.html">GNU GPL</a>. The runtime
1070 libraries are under the <a
1071 href="http://www.opensource.org/licenses/lgpl-license.html">GNU
1072 Library GPL</a>. And the class libraries are released
1073 under the terms of the <a
1074 href="http://www.opensource.org/licenses/mit-license.html">MIT X11</a>
1077 Q: I would like to contribute code to Mono under a particular
1078 license. What licenses will you accept?
1080 A: We will have to evaluate the licenses for compatibility first,
1081 but as a general rule, we will accept the code under the same
1082 terms of the "container" module.
1084 <a name="patents"></a>
1087 Q: Could patents be used to completely disable Mono (either submarine
1088 patents filed now, or changes made by Microsoft specifically to
1089 create patent problems)?
1091 A: No. First, its basic functional capabilities have pre-existed too
1092 long to be held up by patents. The basic components of Mono are
1093 technologically equivalent to Sun's Java technology, which has been
1094 around for years. Mono will also implement multi-language and
1095 multi-architecture support, but there are previous technologies
1096 such as UCSD p-code and ANDF that also support multiple languages
1097 using a common intermediate language. The libraries are similar
1098 to other language's libraries, so again, they're too similar to
1099 be patentable in large measure.
1101 However, if Microsoft does patent some technology, then our plan is
1102 to either (1) work around it, (2) chop out patented pieces, (3)
1103 find prior art that would render the patent useless.
1105 Not providing a patented capability would weaken the
1106 interoperability, but it would still provide the free software /
1107 open source software community with good development tools, which
1108 is the primary reason for developing Mono.
1111 ** Miscellaneous Questions
1113 Q: You say that the CLI allows multiple languages to execute on the
1114 same environment. Isn't this the purpose of CORBA?
1116 A: The key difference between CORBA (and COM) and the CLI is that the
1117 CLI allows "data-level interoperability" because every
1118 language/component uses the same data layout and memory management.
1120 This means you can operate directly upon the datatypes that someone
1121 else provides, without having to go via their interfaces. It also
1122 means you don't have to "marshall" (convert) parameters (data
1123 layouts are the same, so you can just pass components directly) and
1124 you don't have to worry about memory managment, because all
1125 languages/components share the same garbage collector and address
1126 space. This means much less copying and no need for reference
1129 Q: Will you support COM?
1131 A: The runtime will support XPCOM on Unix systems and COM on Windows.
1132 Most of the code for dynamic trampolines exists already.
1134 Q: Will Ximian offer certifications on Mono or related technologies?.
1136 A: It's possible. But there is no plan about this. So the short answer is no.
1138 Q: Are there any Boehm's gc binaries?
1140 A: Yes. You can find RPMs <a href="http://java.thn.htu.se/~toor/">here</a>, though
1141 if your distribution provides the correct packages, you should use those.
1142 The suggested version of the Boehm GC is 6.1.
1144 Q: How can I report a bug?
1146 A: The best thing is to track down the bug and provide a simple test to
1147 reproduce the bug. You can then add the bug to
1148 <a href="http://bugzilla.ximian.com/enter_bug.cgi">bugzilla</a> or
1149 simply send it to mono-list@ximian.com. Please provide info about
1150 what version of mono you're using and any relevant details to be
1151 able to repoduce the bug. Note that bugs reported on the mailing-list
1152 may be easily forgotten, so it's better to file them in bugzilla.
1154 Q: Does mcs support the same command line options as the MS C#
1157 A: The Mono C# compiler now supports the same command line
1158 arguments as the Microsoft C# compiler does.
1160 Q: How about getting searchable archives on lists.ximian.com?
1162 A: You can perform a search on the mono-related mailing lists
1163 <a href="http://www.go-mono.com/mailing-lists.html">here</a>.
1165 Q: When using mono from cvs or from a snapshot, I get an error messaage
1166 saying that Mono and the runtime are out of sync. How do I fix that?
1168 A: If you use mono from cvs, you need to be prepared for changes in the
1169 runtime internals. This means that you should keep a working setup
1170 before blindling updating (a working setup may just be the last released
1171 tarball or a recent binary snapshot).
1172 Usually, compiling corlib with mcs before recompiling the C runtime does
1173 the right thing (but occasionally you may need to do it the other
1178 <a name="problems"></a>
1179 ** Mono Common Problems
1181 If you are having problems compiling or running Mono software
1182 or if you think that you found a bug, etc. Please visit the
1183 <a href="http://geneura.ugr.es/~jaime/mono-common-problems.html">Mono Common Problems</a> document and try there.