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>
23 href="http://www.es.gnome.org/documentacion/articulos/MONO-PUF/MONO-PUF/">spanish
24 translation</a> is also available
29 Q: What is Mono exactly?
31 A: The Mono Project is an open development initiative sponsored by
32 Ximian that is working to develop an open source, Unix
33 version of the Microsoft .NET development platform. Its objective
34 is to enable Unix developers to build and
35 deploy cross-platform .NET Applications. The project will
36 implement various technologies developed by Microsoft that have now
37 been submitted to the ECMA for standardization.
39 Q: What is the difference between Mono and the .NET Initiative?
41 A: The ".NET Initiative" is a somewhat nebulous company-wide effort by
42 Microsoft, one part of which is a cross-platform development
43 framework. Mono is an implementation of the development framework,
44 but not an implementation of anything else related to the .NET
45 Initiative, such as Passport, software-as-a-service, or
48 Q: What technologies are included in Mono?
50 A: Mono contains a number of components useful for building new
54 * A Common Language Infrastructure (CLI) virtual
55 machine that contains a class loader, Just-in-time
56 compiler, and a garbage collecting runtime.
58 * A class library that can work with any language
59 which works on the CLR.
61 * A compiler for the C# language. In the future we
62 might work on other compilers that target the Common
67 Windows has compilers that target the virtual machine from <a
68 href="http://msdn.microsoft.com/net/thirdparty/default.asp#lang">a
69 number of languages:</a> Managed C++, Java Script, Eiffel,
70 Component Pascal, APL, Cobol, Perl, Python, Scheme,
71 Smalltalk, Standard ML, Haskell, Mercury and Oberon.
73 The CLR and the Common Type System (CTS) enables applications and
74 libraries to be written in a collection of different languages that
77 This means for example that if you define a class to do algebraic
78 manipulation in C#, that class can be reused from any other
79 language that supports the CLI. You could create a class in C#,
80 subclass it in C++ and instantiate it in an Eiffel program.
82 A single object system, threading system, class libraries, and
83 garbage collection system can be shared across all these languages.
85 Q: Where can I find the specification for these technologies?
87 A: You can find the work-in-progress documentation from the T3G ECMA
90 <a href="http://www.dotnetexperts.com">http://www.dotnetexperts.com</a>
92 Q: Will you implement the .NET Framework SDK class libraries?
94 A: Yes, we will be implementing the APIs of the .NET Framework SDK
97 Q: Will you offer an ECMA-compliant set of class libraries?
99 A: Eventually we will. Our current focus is on interoperating
100 with the Microsoft SDK, but we will also offer an ECMA compliant
103 Q: What does the name "Mono" mean?
105 A: Mono is the word for `monkey' in Spanish. We like monkeys.
109 A: The JIT engine is usable on Intel x86 machines. An interpreter
110 can be used on other non-Intel x86 machines.
112 The class libraries are mature enough to run some real applications
113 (the compiler for instance, and every day more and more applications
114 are natively developed with Mono).
116 Q: When will you ship it?
118 A: Different parts of Mono will achieve usability at different stages,
119 once we are comfortable with the compiler, we will release "Mono Core",
120 which contains everything needed to develop applications with the base
121 class libraries. This should be available at some point during 2002.
123 Other higher level class libraries (ASP.NET, ADO.NET) will
124 be released when they become stable.
126 Q: What major components will you include in Mono?
128 A: Hopefully everything that Microsoft ships on their Framework
129 (ADO.NET, ASP.NET), and
130 we encourage third party developers to create reusable components that
131 work on both Mono and Windows.
133 Q: How can I contribute?
135 A: Check the <a href="contributing.html">contributing</a> section.
137 Q: Aren't you just copying someone else's work?
139 A: We are interested in providing the best tools for programmers to
140 develop applications for Free Operating Systems. We also want to help
141 provide the interoperability that will allow those systems to fit in
142 with other standards.
144 For more background, read the <a href="http://www.go-mono.com/rationale.html">Mono
145 Project white paper</a>.
148 Q: Miguel said once that Mono was being implemented in COBOL. Is that true?.
150 A: No. It was a joke.
153 <a name="ximian"></a>
155 ** The Ximian Role in the Mono Project
157 Q: Why is Ximian working on .NET?
159 A: Ximian is interested in providing the best tools for programmers to
160 develop applications for Free Operating Systems.
162 For more information, read the project <a
163 href="rationale.html">rationale</a> page.
165 Q: Will Ximian be able to take on a project of this size?
167 A: Of course not. Ximian a supporter of the Mono project, but the only way
168 to implement something of this size is for the entire free software
169 community to get involved. Visit the <a href="contributing.html">contributing</a>
170 page if you'd like to help out.
172 Q: What pieces will Ximian be working on?
174 A: We will devote most of our resources to work on the pieces which are
175 on the critical path to release a development and execution
176 environment. Once the project is at a stage where it is useful in
177 the real world, it will achieve a critical mass of developers to
180 Q: Will Ximian offer Mono commercially?
182 A: When Mono is ready to be shipped Ximian will offer a commercial
183 support and services for Mono.
185 Q: Does Ximian provide consulting services around Mono?
187 A: Yes, Ximian does provide consulting services around Mono to
188 make it suitable to your needs. Porting the runtime engine,
189 customizing it, working on specific classes or tuning the code
190 for your particular needs.
192 Q: Will you wait until Mono is finished?
194 A: Mono will ship on various stages as they mature. Some people
195 require only a subset of the technologies, those will ship first.
197 More advanced features will take more time to develop. A support
198 timeline will be available in June 2002.
203 Q: How is Mono related to GNOME?
205 A: In a number of ways. This project was born out of the need of
206 providing improved tools for the GNOME community, and will use
207 existing components that have been developed for GNOME when they
208 are available. For example, we plan to use Gtk+ and Libart to
209 implement Winforms and the Drawing2D API and are considering
212 Q: Has the GNOME Foundation or the GNOME team adopted Mono?
214 A: Mono is too new to be adopted by those groups. We hope that the
215 tools that we will provide will be adopted by free software
216 programmers including the GNOME Foundation members and the GNOME
219 Q: Should GNOME programmers switch over to Mono now?
221 A: It is still far to early for discussions of "switching over." No
222 pieces of Mono will be ready within the next six months, and a
223 complete implementation is roughly one year away.
225 We encourage GNOME developers to continue using the existing tools,
226 libraries and components. Improvements made to GNOME will have an
227 impact on Mono, as they would be the "backend" for various classes.
229 Q: Will Mono include compatibility with Bonobo components? What is the
230 relationship between Mono and Bonobo?
232 A: Yes, we will provide a set of classes for implementing and using
233 Bonobo components from within Mono. Mono should allow you to write
234 Bonobo components more easily, just like .NET on Windows allows you
235 to export .NET components to COM.
237 Q: Does Mono depend on GNOME?
239 A: No, Mono does not depend on GNOME. We use a few packages produced by
240 the GNOME team like the `glib' library.
242 Q: But will I be able to build GNOME applications?
244 A: Yes, we will enable people to write GNOME applications using Mono.
246 Q: Do you have C# bindings for GNOME?.
248 A: Yes, we currently bind libgnome, libgnomecanvas, and libgnomeui --
249 although I dare say I have no idea how functional the bindings are
250 outside of what I tested in the sample app. I imagine other libraries
251 under the GNOME framework will be added on an as-needed (and as-requested)
252 basis...although a truly good bonobo binding will have to wait on the CORBA
253 remoting support which has been started recently.
258 Q: Will Mono enable GUI applications to be authored?
260 A: Yes, you will be able to build GUI applications. Indeed, that is our
261 main focus. We will provide both the Windows.Forms API and the Gtk# API.
263 Q: What is the difference between Gtk# and System.Windows.Forms?
265 A: Gtk# is a set of bindings for the Gtk+ toolkit for C# (and other
266 CIL-enabled languages). System.Windows.Forms is an API defined
267 by Microsoft to build GUI applications.
269 Q: Will I be able to run my smart clients on systems powered by Mono?
271 A: As long as your applications are 100% .NET and do not make use
272 of P/Invoke to call Win32 functions, your smart client applications
273 will run on Mono platforms.
275 Q: Where can I learn mora about Gtk#?
277 A: The following <a href="http://gtk-sharp.sourceforge.net>link</a> sends you to the page of the project.
279 Q: What can I do with Gtk#?.
281 A: Gtk# is becoming very usable and you can create applications and
282 applets like those you see in a GNOME desktop environment. It's
283 easy to install so it's worth a try.
285 Q: How can I compile my HelloWorld.cs which uses Gtk#?.
287 A: Try: mcs --unsafe -o HelloWorld.exe -r glib-sharp -r pango-sharp -r
288 atk-sharp -r gdk-sharp -r gtk-sharp -r gdk-imaging-sharp
291 Q: Is there any way how to connect DataAdapter to some GTK# controls?
293 A: There is a sample file called `DbClient' in gtk-sharp/samples that you
294 might to look at. It is a sample program in Gtk# that adds/updates/deletes
295 information on a Postgress database. When we have the new table/tree widgets,
296 I am sure someone would write an adapter for System.Data (in Gtk2 the
297 tree/list widgets are written using a view/model, so you only need to write
298 a model that maps to the database). You can have a look at
299 gtk-sharp/sample/DbClient, where there is a GTK# application that uses
300 System.Data. It does not use DataAdapter, but DataReader though.
302 <a name="winforms"></a>
305 Q: Can you tell me why aren't you implementing WinForms?.
307 A: (This is based in an original mail to mono-list written by Miguel de
308 Icaza. You should read it for completion, but the core part is here).
310 First, Windows.Forms is packed with quirks and is not that great of a
311 toolkit in the first place. Up to the point of the unconfirmed rumor
312 that Microsoft is working on a replacement for it.
314 Once the runtime is done, we will very likely start contributing to
315 the Gtk# project ourselves, and we will likely start doing feasibility
316 work on getting Mono used by Gnome developers: full gnome apps and
317 extending existing applications.
319 Those interested in hacking on Windows.Forms are welcome to do so,
320 but Ximian will not likely look at it in the near future; if there is
321 enough demand, or I can be convinced that Windows.Forms is useful for
322 something Ximian might re-evaluate our resource allocation for this
325 By doing native ports, we could use the same API on all those systems.
326 Also, Gtk is mature enough, we know this because we have built an entire
327 desktop (and all sorts of very window system-specific hacks), and we
328 have built a bunch of productivity applications with it.
332 Someone mentioned VCL. The only problem with the VCL is that it can
333 only be used for GPL applications (or I guess you could license it from
334 Borland for your app), and would have to be ported from Delphi to C#
335 (or someone would have to write a CIL compiler for it).
337 Q: What about doing something like the eclipse project (www.eclipse.org)?
339 A: The Eclipse toolkit is not a general purpose toolkit. It will require a
340 lot of work before it is such a thing. It is a toolkit used to
341 implement a development environment.
345 ** Mono and Microsoft
347 Q: Is Microsoft helping Ximian with this project?
349 A: No. Ximian CTO Miguel de Icaza had a friendly conversation with
350 Microsoft software architect David Stutz, but that's about the
351 extent of the contact. Microsoft is interested in other
352 implementations of .NET and are willing to help make the ECMA spec
353 more accurate for this purpose.
355 Ximian representatives have also spoken with Sam Ruby at the ECMA
356 TG3 committee to discuss the same issues.
358 Q: Is Microsoft or Corel paying Ximian to do this?
362 Q: Do you fear that Microsoft will change the spec and render Mono
365 A: No. Microsoft proved with the CLI and the C# language that it was
366 possible to create a powerful foundation for many languages to
367 interoperate. We will always have that.
369 Even if changes happened in the platform which were undocumented,
370 the existing platform would a value on its own.
372 Q: Are you writing Mono from the ECMA specs?
374 A: Yes, we are writing them from the ECMA specs and the published
375 materials in print about .NET.
377 Q: If my applications use Mono, will I have to pay a service fee?
379 A: No. Mono is not related to Microsoft's initiative of
380 software-as-a-service.
382 Q: Is the Mono Project is related to the Microsoft Hailstorm effort? Is
383 Ximian endorsing Hailstorm?
385 A: No. The Mono Project is focused on providing a compatible set of
386 tools for the Microsoft .NET development platform. It does not
387 address, require, or otherwise endorse the MS Passport-based
388 Hailstorm single sign-on system that is part of Windows XP and
391 Q: Will Mono or .NET applications depend on Microsoft Passport?
393 A: No. MS Passport is unrelated to running .NET compatible applications
394 produced with the Mono tools. The only thing you will need is a
395 just-in-time compiler (JIT).
397 Q: What is a 100% .NET application?
399 A: A `100% .NET application' is one that only uses the APIs defined
400 under the System namespace and does not use PInvoke. These
401 applications would in theory run unmodified on Windows, Linux,
402 HP-UX, Solaris, MacOS X and others.
404 Q: If Microsoft will release a port of their .NET platform under the
405 `Shared Source' license, why should I bother with anything else?
407 A: The Shared Source implementation will be expensive and its uses
408 will be tightly restricted, especially for commercial use. We are
409 working towards an implementation that will grant a number of
410 important rights to recipients: use for any purpose,
411 redistribution, modification, and redistribution of modifications.
413 This is what we call <a
414 href="http://www.gnu.org/philosophy/free-sw.html">Free Software</a>
416 Q: Is Mono a free implementation of Passport?
418 A: No. Mono is just a runtime, a compiler and a set of class
421 Q: Will the System.Web.Security.PassportIdentity class mean
422 that my software will depend on Passport?
424 A: No. Applications may use that API to contact a Passport site, but
425 are not required to do so.
427 As long as your application does not use Passport, you will not
430 Q: Will Mono running on Linux make Passport available for Linux?
432 A: No. However, the Passport toolkit for Linux-based web servers is
433 available from Microsoft.
435 Q: Will Mono allow me to run Microsoft Office on Linux?
437 A: No, it will not. Microsoft Office is a Windows application. To
438 learn more about running Windows applications on Intel Unix systems
439 refer to <a href="http://www.winehq.com">the Wine Project</a>.
441 Q: Will I be able to compile a Microsoft VB.NET application and execute
442 the resultant MSIL file under MONO on Linux without converting to C#
445 A: Once we have a complete VisualBasic runtime, yes.
447 Q: Can mono run the WebMatrix ?
449 A: No. That requires winforms (we don't have).
451 Q: Does mono have something like Passport ? (ie PassportIdentity class,somewhere
452 in System.Web ?) . Will mono have a server side Passport/Similar framework
453 for XSP as well as client classes ?
455 A: Not yet, but the client side API for authentication is not the problem.
456 We will likely have a lot of other authentication APIs, like the Liberty
457 Aliance APIs. The problem is people on the web provider end that might use
458 this for authentication.
460 <a name="pnpproject"></a>
461 ** Mono and Portable.NET
463 Q: What are the differences between Mono and Portable.NET?
465 A: Most of Mono is being written using C#, with only
466 a few parts written in C (The JIT engine, the runtime, the
467 interfaces to the garbage collection system).
469 It is easier to describe what is unique about Mono:
471 <li> A self-hosting C# compiler written in C#, which is clean, easy
474 <li> A multi-platform runtime engine: both a JIT engine and an
475 interpreter exist. The JIT engine runs currently on x86
476 systems, while the interpreter works on Sparc, StrongARM and
479 <li> Supports Linux, Windows and Solaris at this point.
481 <li> The JIT engine is written using a portable instruction
482 selector which not only generates good code (we are told
483 that we are faster than Rotor, but it is hard to tell) but
484 is also the foundation to retarget the JIT engine to other
487 The system employed is described in various compiler
488 books and it is very similar to what is described in the
489 book that covers LCC, the Ansi C retargetable C compiler.
491 <li> The JIT engine supports inlining, constant folding and propagation,
493 <li> Full support for remoting in the runtime, but the class
494 libraries are still behind.
496 <li> The C# compiler, the JIT engine and the class libraries are
497 mature enough that the whole system is self-hosting, ie, that
498 it can be fully developed with itself at this point.
500 <li> We are not yet done, and there is a lot of work left to be
503 <li> We have a great community of developers, without which Mono
504 would not be possible.
506 <li> We will provide an ahead of time compilation mode in the
510 <a name="webservices"></a>
513 Q: How is Mono related to Web Services?
515 A: Mono is only related to Web Services in that it will implement the
516 same set of classes that have been authored in the .NET Framework
517 to simplify and streamline the process of building Web Services.
519 But most importantly, Mono is an Open Source implementation of the
522 Q: Can I author Web Services with Mono?
524 A: You will be able to write Web Services on .NET that run on Mono and
527 Q: If Mono implements the SDK classes, will I be able to write and
528 execute .NET Web Services with it?
530 A: Yes. When the project is finished, you will be able to use the
531 same technologies that are available through the .NET Framework SDK
532 on Windows to write Web Services.
534 Q: What about Soup? Can I use Soup without Mono?
536 A: Soup is a library for GNOME applications to create SOAP servers and
537 SOAP clients, and can be used without Mono. You can browse the
538 source code for soup using <a
539 href="http://cvs.gnome.org/bonsai">GNOME's Bonsai</a>.
543 A: Yes. The CLI contains enough information about a class that
544 exposing it to other RPC systems (like CORBA) is really simple, and
545 does not even require support from an object.
547 We will be implementing CORBA interoperation as an extension to the
548 Mono classes so that we can integrate with Bonobo, just like
549 Microsoft provides COM interoperation classes and support
552 Q: Can I serialize my objects to other things other than XML?
554 A: Yes, although the serializing tools have not yet been planned, and
555 you would probably have to implement them yourself.
557 Q: Will Mono use ORBit?
559 A: No. Mono will be using a new implementation of CORBA that isn't still started.
562 ** Development Tools and Issues
564 Q: Will it be possible to use the CLI features without using bytecodes
567 A: Yes. The CLI engine will be made available as a shared library.
568 The garbage collection engine, the threading abstraction, the
569 object system, the dynamic type code system and the JIT will be
570 available for C developers to integreate with their applications if
573 Q: Will you have new development tools?
575 A: With any luck, Free Software enthusiasts will contribute tools to
576 improve the developer environment. These tools could be developed
577 initially using the Microsoft implementation of the CLI and then
578 executed later with Mono.
580 Q: What kind of rules make the Common Intermediate Language useful for
583 A: The main rule is that the stack in the CLI is not a general purpose
584 stack. You are not allowed to use it for other purposes than
585 computing values and passing arguments to functions or return
588 At any given call or return instruction, the types on the stack
589 have to be the same independently of the flow of execution of your
592 Q: Is it true that the CIL is ideal for JITing and not efficient for
595 A: The CIL is better suited to be JITed than JVM byte codes, but you
596 can interpret them as trivially as you can interpret JVM byte
599 Q: Isn't it a little bit confusing to have the name of "XSP" (the same
600 as in the Apache Project) for the ASP.NET support in Mono?.
602 A: In Mono, xsp is just the name of the C# code generator for ASP.NET
603 pages. In the Apache Project, it is a term for the "eXtensible Server
604 Pages" technology so as they are very different things, they don't
607 Q: What about using something like Jabber instead of the System.Messaging
610 A: In short, MSMQ is not something like Jabber, but asynchronous messaging
611 through queues. Usefull queues do more than serialize messages, they are
612 also platform bridges.
614 Q: Are you supporting XMLDocument and relatives?.
616 A: Currently, we aren't implementing them yet. It would require updates to
617 most of the XmlNode derivatives so it's not a trivial task. We are
618 currently focusing on getting XPath support working.
620 Q: Is there any plan to develop an aspx server for Mono?.
622 A: The webserver turned out to be very simple compared to the rest of the
623 work. Gonzalo has got the page generator mostly done (a module called
624 xsp, who has nothing to do with the XSP term used in the Apache Project).
625 Patrik has done a lot of the work to get the ProcessRequest to work.
626 You can try to help in the final touches to the System.Web classes and
627 writing regression tests for the widgets we have.
629 Q: Is there any way I can develop the class libraries using linux yet?
631 A: Yes. Some class libraries can be developed on Linux. Search for
632 Paolo's post (he lists which classes can be compiled fine now).
634 Q: Is there any way I can install a known working copy of mono in /usr,
635 and an experimental copy somewhere else, and have both copies use
636 their own libraries? (I'm still not very good at library paths in
639 A: Yes. Just use two installation prefixes.
641 Q: How should I write tests or a tests suite?
643 A: If you do a test suite for C#, you might want to keep it
644 independent of the Mono C# compiler, so that other compiler
645 implementations can later use it.
647 Q: Is the current stage the implementation of mono_create_trampoline
648 function? Hence the sparc-codegen.h is reasonably complete? Is
649 mono/arch/x86/* the best reference material for this stuff?
651 A: sparc-codegen.h is basically complete. We may want to add some
652 convenience macros along the way, but it has all the stuff you need.
653 And yes, or, the ppc/ dir, since the ppc call convention is more similar
654 to the sparc one than the x86 one. The current issues with the sparc
656 1) it needs to handle overflowing the out registers (the additional
657 arguments need to be put on the stack)
658 2) it needs to flush the icache where the generated code is stored
659 3) it needs to implement mono_create_method_pointer to get delegates
661 4) it needs a couple of updates (mono_method_pointer_get is no longer
664 Q: Would it be too terrible to have another corlib signed as mscorlib?
666 A: We rename corlib to mscorlib also when saving the PE files, in fact,
667 the runtime can execute program created by mono just fine.
669 Q: How do I build corlib under Linux?
671 A: You can build your own (see the web site on how to get the mcs
672 project from cvs), but in order to build them using mcs you need a
673 set of working class libraries. After building the runtime (using
674 mono-build.sh) get them from the nightly build and put them (and
675 mcs.exe) in your mono/install/lib directory. Then you should be able
676 to do: cd mcs, then: make -f makefile.gnu, then: cp mcs/mcs.exe
677 class/lib/*.dll ../install/lib Also, you should know that you can
678 either get your dose of DLLs from MonoCharge, or from
679 http://primates.ximian.com/~miguel/runtime. MonoCharge is updated
680 automatically, while the later is only updated when Miguel is around
681 Once you have the DLLs, you can use `make -f makefile.gnu' as described
684 Q: Is there a relatively straightforward way to repeat the steps taken
685 by Paolo to get Mono completely self-hosted on linux?
687 A: To build the compiler and class libraries in Linux, run:
688 <ul><li>make -f makefile.gnu. To install them, run: </li>
689 <li>make -f makefile.gnu install</li>
690 <li>You can also specify a prefix:</li>
691 <li>make -f makefile.gnu install prefix=/opt</li>
693 If you want to produce and distribute a monocharge tarball, run:
694 make -f makefile.gnu dist
695 Of course you have to run these in the top level mcs directory.
697 Q: Is it possible to build a C# file to some sort of intermediate format which
698 can linked into a final module, like the traditional .c -> .o -> .so path?
700 A: You could do: mcs /target:module file1.cs, mcs /target:module file2.cs,
701 mcs /target:exe file1.dll file2.dll /out:mybin.exe
703 Q: Is there any plans for implementing remoting in the near future?, When will
704 work in System.Runtime.Remoting.dll start?
706 A: The remoting infrastructure is in place. Some of the channels and
709 Q: I'm wondering if there are any plans to start using nant to build the
710 class lib + test lib. i think that every project neeed/should use an
711 automated build process and nant + a couple of tools enables this. is
712 the problem that the compiler can't run nant yet?
714 A: Maybe well be doing some sort of automated build process + testing when
720 Q: Is Mono supporting ASP.NET?
722 A: Yes. The development of the support for ASP.NET comes in various stages,
723 here is what Gonzalo has been working on: 1. The Parser. 2. Getting the
724 parser to generate output compatible with ASP.NET. 3. Running the sample
725 output with the real Microsoft runtime but using our generated page. 4.
726 Running the sample with our classes with the .NET runtime. 5. Running
727 our sample code with our classes with our runtime. This is the process
728 we are following. Currently Gonzalo has reached point 5.
730 Q: Do I need install cygwin to work on ASP.NET in mono or Linux is enough since
731 it is self host right now.
735 Q: Any plan to make ASP.NET in mono works with Apache in linux?.
737 A: Yes, we have plans to do so, but we need to wait for Patrik's patches to
738 HttpRuntime. Once that is there, writing a mod_mono should be trivial
739 (look at mono/samples/embed for a sample embedded application).
744 Q: What is the status of ADO.NET support?. Could I start migrating
745 applications from MS.NET to Mono?.
747 A: You could start right now using the ADO.NET support in mono, of course,
748 if you want to help filling the missing gaps while you develop your app
749 :-) Well, what I mean is that we're not that far to having full ADO.NET
750 support in Mono, and we've got a lot of working things, so if we could
751 get more help, we'd finish it really soon :-)
753 Q: In developing the data architecture for the application are there and
754 objects I should stay away from in order to insure the smoothest possible
755 transition (minimum code rewrite) to Mono's ADO.NET implementation? (For
756 example, strongly typed datasets versus untyped datasets, etc...)
758 A: we are implementing all the classes in Microsoft .NET's System.Data, so
759 you can be sure that things will work the same in Mono as with the MS's
760 implementation. We'll maybe provide extra classes to fix some things
761 we've found missing while developing ADO.NET in Mono, but if you keep
762 using the MS's System.Data classes, things will work out of the box with
763 no changes (or at least that's the plan :-)
768 Q: Why don't you use Java? After all, there are many languages that
771 A: You can get very good tools for doing Java development on free
772 systems right now. <a href="http://www.redhat.com">Red Hat</a> has
773 contributed a <a href="http://gcc.gnu.org">GCC</a> <a
774 href="http://gcc.gnu.org/java">frontend for Java</a> that can take
775 Java sources or Java byte codes and generate native executables; <a
776 href="http://www.transvirtual.com">Transvirtual</a> has implemented
777 <a href="http://www.kaffe.org">Kaffe</a> a JIT engine for Java;
778 Intel also has a Java VM called <a
779 href="http://www.intel.com/research/mrl/orp">ORP</a>.
781 The JVM is not designed to be a general purpose virtual machine.
782 The Common Intermediate Language (CIL), on the other hand, is
783 designed to be a target for a
784 wide variety of programming languages, and has a set of rules
785 designed to be optimal for JITers.
787 Q: Could Java target the CLI?
789 A: Yes, Java could target the CLI. We have details on a <a
790 href="ideas.html#guavac">project</a> that someone could take on to
793 Microsoft has an implemenation of the Java language called J# that
794 can target the CIL execution engine.
796 Q: Is it possible to write a JVM byte code to CIL convertor?
798 A: Yes, it is possible. Here are a few starting point:
801 * A byte code representation is really a flattened forest of
802 trees. Look at the Mono JIT engine to see how we compute
803 the basic blocks (this is used to figure out the "trees").
805 The forest is just an array of trees.
807 Indeed, run the JIT engine with -d (mono -d prog.exe) and
808 you will see how these trees look like.
810 You will have to do something similar for Java.
812 * Each "forest of trees" has a meaning. This meaning can now
813 be translated into the equivalent "meaning" in CLR-land.
816 Q: Could mono become a hybrid cil/java platform?
818 A: No. It is quite far from the philosophy of the project. The idea of Mono
819 is, to have only _one_ VM, on which all can run. And if there existing a
820 binary-converter from Java-.class to IL and if there existing something
821 like J-Sharp on Mono, you can write programs in Java, which than can run
822 on Mono. You do not need two bindings (like your example: GTK-Sharp _and_
823 Java-Gnome). You need only _one_ of it (GTK-Sharp). Thats the idea of Mono.
824 An other point is, that there are no people, who use OpenSource-JVMs. They
825 all prefer Suns original. But for Unix there don't exist a .NET-Framework.
826 So it is possible, that in the future Mono is the standard .NET for unixes.
828 Q: Do you plan to implement a Javascript compiler?
830 A: Yes. Eto Demerzal has started a Rhino port to C#.
831 After this is completed, we will begin developing
832 the Javascript compiler.
834 <a name="extending"></a>
837 Q: Would you allow other classes other than those in the
840 A: Yes. The Microsoft class collection is very big, but it is by no
841 means complete. It would be nice to have a port of `Camel' (the
842 Mail API used by Evolution inspired by Java Mail) for Mono
845 You might also want to look into implementing CORBA for Mono. Not
846 only because it would be useful, but because it sounds like a fun
847 thing to do, given the fact that the CLI is such a type rich
850 For more information on extending Mono, see our <a
851 href="ideas.html">ideas</a> page.
853 Q: Do you plan to Embrace and Extend .NET?
855 A: Embracing a good technology is good. Extending technologies in
856 incompatible ways is bad for the users, so we do not plan on
857 extending the technologies.
859 If you have innovative ideas, and want to create new classes, we
860 encourage you to make those classes operate correctly well in both
863 Q: Is there any way I can develop the class libraries using linux yet?
865 A: Yes. Some class libraries can be developed on Linux. Search for
866 Paolo's post (he lists which classes can be compiled fine now).
868 Q: Is there any way I can install a known working copy of mono in /usr,
869 and an experimental copy somewhere else, and have both copies use
870 their own libraries? (I'm still not very good at library paths in
873 A: Yes. Just use two installation prefixes.
876 <a name="portability"></a>
879 Q: Will Mono only work on Linux?
881 A: Currently, we are doing our work on Linux-based systems and
882 Windows. We do not expect many Linux-isms in the code, so it
883 should be easy to port Mono to other UNIX variants.
885 Q: What about Mono on non Linux-based systems?
887 A: Our main intention at Ximian is to be able to develop GNOME
888 applications with Mono, but if you are interested in providing a
889 port of the Winform classes to other platforms (frame buffer or
890 MacOS X for example), we would gladly integrate them, as long
891 they are under an open source license.
893 Q: What operating systems/CPUs do you support
895 A: Mono currently runs on Linux, Windows, Solaris and FreeBSD.
896 There is a JIT engine available for x86 processors that can
897 generate code and optimizations tailored for a particular CPU.
899 Interpreters exist for the SPARC, PowerPC and StrongARM cpus.
901 Q: Does Mono run on Windows?
903 A: Yes. The Compiler and the runtime both run on Windows.
905 Q: When will mono and mcs compile on Linux?.
907 A: That happend a long time ago. Know you can download and compile
908 them or even install them from already made binary packages for
909 Windows and for Linux (RPM/DEB).
911 Q: Will I require Cygwin to run mono?
913 A: No. While you'll need it to compile it, it runs without cygwin and does not even require cygwin1.dll
915 Q: Will Mono depend on GNOME?
917 A: It will depend only if you are using a particular assembly (for
918 example, for doing GUI applications). If you are just interested
919 in Mono for implementing a `Hello World Enterprise P2P Web
920 Service', you will not need any GNOME components.
922 Q: Is anyone working on porting Mono to IA-64?
924 A: Nobody is working on such port.
926 Q: If I were about to start a Mono port to IA-64,would the same lburg code
927 generator work for IA-64 also? or anything else need to be used for code
928 generation(as the processor architecture is totally different from IA32)
930 A: The lburg approach can be use for any processor architecture. But you might
931 think in another better approach.
933 Q: Do you plan to port Rhino to C#?.
935 A: Eto Demerzal has started a Rhino port to C#.
937 Q: Has anyone succeeded in building a Mac version of the C# environment.
938 If so can you explain how?
940 A: You could try to check with the Darwin people, or the Fink people.
941 Mono/C# is self hosting on Linux/PPC which is the hard part, so it
942 should be relatively simple to get it to work on macos
945 ** Reusing Existing Code
947 Q: What projects will you reuse or build upon?
949 A: We want to get Mono in the hands of programmers soon. We are
950 interested in reusing existing open source software.
952 Q: What about Intel's research JIT framework, ORP?
954 A: At this time, we are investigating whether we can use elements of
955 ORP for Mono. ORP is a research JIT engine that has a clearly
956 defined API that splits the JIT from the GC system and the actual
957 byte code implementation.
959 We are using some pieces of ORP (Their code generation interface)
960 and we use it as a source of inspiration for optimizations. Paolo
961 and Dietmar consider ORP as being one of the best JIT engines out
962 there (and their research work and papers are very useful if you are
963 interested in JIT technology).
965 Q: What about using GNU Lightning?
967 A: We are not using GNU Lightning. Our JIT is using an instruction
968 selector based on tree-pattern matching, and a code generation
969 interface that is very tied to the current architecture.
971 Q: Will I be able to use Microsoft SQL Server 2000 or will I need to switch
972 to a specific Open Source Database. Will I need to recode?
974 A: There should not be any need to recode.
976 Q: What do I need to watch out for when programming in VB.NET so that I'm
977 sure to be able to run those apps on Linux?
979 A: Not making any PInvoke or DLL calls should and not using anything in
980 the Microsoft.* namespaces should suffice. Also do not use any
981 Methods/Classes marked as "This type/method supports the .NET Framework
982 infrastructure and is not intended to be used directly from your code."
983 even if you know what these classes/methods do.
985 Q: Will built-in reporting be supported for crystal reports? This is a
986 heavily used part of our system.
988 A: Probably not. Crystal Reports are propriety. Someone may try to emulate
989 the behaviour, but no-one has yet volunteered.
991 Q: Who about writing to the registry? As I understand it, Linux does not have
992 a counterpart to the registry. Should I avoid relying on that feature?
994 A: Try to avoid it. Although there would be a emulation for registry in
995 Mono too. GNOME does have a registry like mechanism for configuration. But
996 Even if gnome has a configuration system similar to the registry, the keys
997 will not be equal, so you will probably end up having to do some runtime
998 detection, and depending on this load an assembly that has your
999 platform-specific hacks.
1001 Q: System.Data.SqlClient with FreeTDS, will you port parts of these to C# and
1004 A: if their license is compatible with mono's, yes, we'd think about porting
1005 them. If not, we'll continue with the plan of using FreeTDS.
1010 Q: Are you working on a GCC front-end to C#? A GCC backend that will
1011 generate CIL images? What about making a front-end to GCC that
1012 takes CIL images and generates native code?
1014 A: We are currently seeking volunteers for those projects.
1015 Visit the <a href="contributing.html">contributing</a> section if
1018 Q: But would this work around the GPL in the GCC compiler and allow
1019 people to work on non-free front-ends?
1021 A: People can already do this by targeting the JVM byte codes (there
1022 are about 130 compilers for various languages that target the JVM).
1024 Q: Why are you writing a JIT engine instead of a front-end to GCC?
1026 A: We want the JIT engine and runtime engine because they will be able
1027 to execute CIL executables generated on Windows, and so no recompilation
1030 <a name="performance"></a>
1033 Q: How fast will Mono be?
1035 A: We can not predict the future, but a conservative estimate is that
1036 it would be at least `as fast as other JIT engines'.
1038 We would like to ship various JIT engines with Mono, just like
1039 Microsoft has done with their .NET development platform. We could
1040 provide a faster, JIT for fast load times but lower performance,
1041 and an and an optimizing JIT that would be slower at generating
1042 code but produce more optimal output.
1044 The CIL has some advantages over the Java byte code: it is really
1045 an intermediate representation and there are a number of
1046 restrictions on how you can emit CIL code that simplify creating
1049 For example, on the CIL, the stack is not really an abstraction
1050 available for the code generator to use at will. Rather, it is a
1051 way of creating a postfix representation of the parsed tree. At
1052 any given call point or return point, the contents of the stack are
1053 expected to contain the same object types independently of how the
1054 instruction was reached.
1056 <a name="licensing"></a>
1059 Q: Will I be able to write proprietary applications that run with
1062 A: Yes. The licensing scheme is planned to allow proprietary
1063 developers to write applications with Mono.
1065 Q: What license or licenses are you using for the Mono Project?
1067 A: The C# Compiler is released under the terms of the <a
1068 href="http://www.opensource.org/licenses/gpl-license.html">GNU GPL</a>. The runtime
1069 libraries are under the <a
1070 href="http://www.opensource.org/licenses/lgpl-license.html">GNU
1071 Library GPL</a>. And the class libraries are released
1072 under the terms of the <a
1073 href="http://www.opensource.org/licenses/mit-license.html">MIT X11</a>
1076 Q: I would like to contribute code to Mono under a particular
1077 license. What licenses will you accept?
1079 A: We will have to evaluate the licenses for compatibility first,
1080 but as a general rule, we will accept the code under the same
1081 terms of the "container" module.
1083 <a name="patents></a>
1086 Q: Could patents be used to completely disable Mono (either submarine
1087 patents filed now, or changes made by Microsoft specifically to
1088 create patent problems)?
1090 A: No. First, its basic functional capabilities have pre-existed too
1091 long to be held up by patents. The basic components of Mono are
1092 technologically equivalent to Sun's Java technology, which has been
1093 around for years. Mono will also implement multi-language and
1094 multi-architecture support, but there are previous technologies
1095 such as UCSD p-code and ANDF that also support multiple languages
1096 using a common intermediate language. The libraries are similar
1097 to other language's libraries, so again, they're too similar to
1098 be patentable in large measure.
1100 However, if Microsoft does patent some technology, then our plan is
1101 to either (1) work around it, (2) chop out patented pieces, (3)
1102 find prior art that would render the patent useless.
1104 Not providing a patented capability would weaken the
1105 interoperability, but it would still provide the free software /
1106 open source software community with good development tools, which
1107 is the primary reason for developing Mono.
1110 ** Miscellaneous Questions
1112 Q: You say that the CLI allows multiple languages to execute on the
1113 same environment. Isn't this the purpose of CORBA?
1115 A: The key difference between CORBA (and COM) and the CLI is that the
1116 CLI allows "data-level interoperability" because every
1117 language/component uses the same data layout and memory management.
1119 This means you can operate directly upon the datatypes that someone
1120 else provides, without having to go via their interfaces. It also
1121 means you don't have to "marshall" (convert) parameters (data
1122 layouts are the same, so you can just pass components directly) and
1123 you don't have to worry about memory managment, because all
1124 languages/components share the same garbage collector and address
1125 space. This means much less copying and no need for reference
1128 Q: Will you support COM?
1130 A: The runtime will support XPCOM on Unix systems and COM on Windows.
1131 Most of the code for dynamic trampolines exists already.
1133 Q: Will Ximian offer certifications on Mono or related technologies?.
1135 A: It's possible. But there is no plan about this. So the short answer is no.
1137 Q: Are there any Boehm's gc binaries?
1139 A: Yes. You can find them <a href="http://java.thn.htu.se/~toor/">here</a>
1141 Q: I have get into trouble when trying to build the site in my Linux box, what
1144 A: Try to change the line "./mono-rss.exe ../index deploy/index.rss" for
1145 "mono ./mono-rss.exe ../index deploy/index.rss"
1147 Q: How can I report a bug?
1149 A: The best thing is to track down the bug and provide a simple test to
1150 reproduce the bug. You can then add the bug to bugzilla:
1151 http://bugzilla.ximian.com/enter_bug.cgi or simply send it to
1152 mono-list@ximian.com.
1154 Q: Does mcs support the same command line options as the MS C#
1157 A: The Mono C# compiler on CVS now supports the same command line
1158 arguments as the Microsoft C# compiler does.
1160 Q: I am thinking about making a VS.NET solution and include as
1161 projects both the library and the System.Xml.dll project
1162 file: is that the best way (sure at the beginning, when the
1163 compiler was not self hosting, you made something similar...)?
1165 A: Jason and Krall did check in VS.NET files that you can use
1166 to compile our System.XML and even to run the System.XML tests
1167 (which is way cool, and way simple).
1169 Q: How about getting searchable archives on lists.ximian.com?
1171 A: You mean like http://www.go-mono.com/mailing-lists.html?
1173 Q: I downloaded the lastest snapshot and did a make and make install on
1174 mono which ran normal but when I tried to do the same with mcs it
1175 errored out with a message saying Mono and Runtime out of sync.
1177 A: You need to compile first the class libraries and install them with your
1178 existing compiler and then the runtime.