3 Q: Is Mono the same as Microsoft's .NET initiative?
7 .NET is a company-wide initiative at Microsoft that
8 encompasses many different areas. The .NET development framework,
9 Passport, Biztalk, new server products, and anything that is
10 remotely connected to .NET gets the ".NET-stamping" treatment.
11 Some components of Microsoft's .NET initiative have been announced
12 and some others are in the works.
14 Mono is a project to implement several technologies developed by
15 Microsoft that have now been submitted to the ECMA Standards Body.
17 Q: What technologies are included in Mono?
19 A: Mono contains a number of components useful for building new
23 * A Common Language Infrastructure (CLI) virtual
24 machine that contains a class loader, Just-in-time
25 compiler, and a garbage collecting runtime.
27 * A class library that can work with any language
28 which works on the CLR.
30 * A compiler for the C# language. In the future we
31 might work on other compilers that target the Common
34 Windows has compilers that target the
36 <a href="http://msdn.microsoft.com/net/thirdparty/default.asp#lang">a
37 number of languages:</a> Managed C++, Java Script,
38 Eiffel, Component Pascal, APL, Cobol, Oberon, Perl,
39 Python, Scheme, Smalltalk, Standard ML, Haskell,
43 The CLR and the Common Type System (CTS) enables applications and
44 libraries to be written in a number of languages. Classes and
45 methods created in one language can be used from a different
48 This means for example that if you define a class to do algebraic
49 manipulation in C#, that class can be reused from any other
50 language that supports the CLI. You could create a class in C#,
51 subclass it in C++ and instantiate it in an Eiffel program.
53 A single object system, threading system, class libraries, and
54 garbage collection system can be shared across all these languages.
56 Q: Where can I find the specification for these technologies?
58 A: You can find the work-in-progress documentation from the T3G ECMA
61 <a href="http://www.dotnetexperts.com">http://www.dotnetexperts.com</a>
63 Q: Will you implement the .NET Framework SDK class libraries?
65 A: Yes, we will be implementing the APIs of the .NET Framework SDK
68 Q: What does Mono stand for?
70 A: Mono is the word for `Monkey' in Spanish. We like monkeys.
72 Q: When will you ship it?
74 A: We do not know when the code will be shipped. The more
75 contributions we get to the project, the sooner it will ship.
77 A rough estimate is that we might be able to run our C# compiler on
78 Linux by the end of the year. That means running the Windows
79 Executable generated by a Microsoft .NET compiler on the Linux
82 We expect that doing GUI applications will require more work on the
83 class libraries. That could take another six months.
85 Q: How can I contribute?
87 A: Check the <a href="contributing.html">contributing</a> section.
89 Q: You guys should innovate instead of copying.
92 We have decided that we should spend our limited resources towards
93 implementing an existing specification instead of designing and
96 Designing and implementing our own would be possible, but it doesn't make
97 sense to do that just because the specification comes from a
102 Q: Why is Ximian working on .NET?
104 A: We are interested in providing the best tools for programmers to
105 develop applications for Free Operating Systems.
107 For more information, read the project <a
108 href="rationale.html">rationale</a> page.
110 Q: Will Ximian be able to take on a project of this size?
112 A: Ximian will not be able to taken on the whole project on its own.
113 Mono will be a free software/open source community project, that is
114 the only way we can hope to implement something of this size. You
115 can <a href="contributing.html">contribute</a> to this effort.
117 Q: What pieces will Ximian be working on?
119 A: We will focus on building a development and execution
122 The idea is to get Mono to a state of that would allow
123 third parties to actually be able to use it real-world development.
125 Q: Why does Ximian even care?
131 Q: What license is Mono on?
133 A: The C# Compiler is released under the terms of the GPL. The
134 class libraries are under the LGPL. The runtime libraries are
137 Q: Will you accept code under the XXX License?
139 A: If the XXX License is compatible with the license we use in that
140 specific piece of code, then yes. If you want to use the BSD license, make
141 sure you use the BSD license without the advertisement clause (The
142 `Ousterhout License').
146 Q: If applications use Mono, does that mean that I have to pay a service fee?
148 A: No. Mono is not related to Microsoft's initiative of
149 software-as-a-service.
151 Q: If you implement .NET, will I depend on Microsoft Passport to run my software?
153 A: No. The .NET Framework is a runtime infrastructure and collection
154 of class libraries. Passport may be required to access certain web
155 services written for that framework, but only if the programmer
156 chooses Passport as the authentication mechanism.
158 Q: Is .NET just a bunch of marketing slogans?
160 A: Although the `.NET initiative' is still quite nebulous, The .NET Framework
161 has been available for some time. Mono is not an implementation of the .NET
162 initiative, just the development framework.
164 Q: What is a 100% .NET application?
166 A: A `100% .NET application' is one that only uses the APIs defined
167 under the System namespace and does not use PInvoke. These
168 applications would in theory run unmodified on Windows, Linux,
169 HP-UX, Solaris, MacOS X and others.
173 Q: Is this a free implementation of Passport?
175 A: No. Passport is part of Microsoft's Hailstorm initiative. Mono
176 is just a runtime, a compiler and a set of class libraries.
178 Q: Will the System.Web.Security.PassportIdentity class, mean
179 that my software will depend on Passport?
181 A: No. That just means that applications might use that API to
182 contact a Passport site.
184 As long as your application does not use Passport, you will not
187 It might even be possible to implement that class with
188 a set of dummy functions, or use an alternate Passport implementation.
190 We do not know at this time whether the Passport protocol is
191 documented and whether we will be able to talk to
196 Q: How is this related to GNOME?
198 A: In a number of ways:
200 * Mono will use existing
201 components that have been developed for GNOME (Gtk+, Libart,
202 Gnome-DB and maybe others).
204 * This project was born out of the need of providing improved
205 tools for the GNOME community.
207 * We would like to add support to our CLR implementation to
208 deal with GObjects (in GNOME 1.x, they are called
209 GtkObjects), and allow Mono developers to provide GObjects
210 or use and extend existing GObjects.
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?
221 A: Mono will not be ready even within the next six months, and a
222 complete implementation is probably one year away.
224 We encourage GNOME developers to continue using the existing tools,
225 libraries and components. Improvements made to GNOME will have an
226 impact on Mono, as they will provide the "backend" for various
229 Q: Will Mono include compatibility with Bonobo components?
231 A: Yes, we will provide a set of classes for implementing and using
232 Bonobo components from within Mono.
236 Q: Is Mono a way of running Java applets?
242 Q: Is Mono just a new way of writing Web Services?
246 Q: If this implements the SDK classes, will I be able to write and
247 execute .NET Web Services with this?
251 When the project is finished, you will be able to use the same
252 technologies that are available through the .NET Framework SDK on
253 Windows to write Web Services.
257 A: Soup is a library for GNOME applications to create SOAP server and
258 SOAP clients. You can browse <a href=Soup here
262 A: Yes. The CLI contains enough information about a class that
263 exposing it to other RPC systems (like CORBA) is really simple, and
264 does not even require support from an object.
266 We will be implementing CORBA interoperation as an extension to the
267 Mono classes so that we can integrate with Bonobo, just like
268 Microsoft provides COM interoperation classes and support
271 Q: Can I serialize my objects to other things other than XML?
273 A: Yes, although the serializing tools have not yet been planned, and
274 you would probably have to implement them yourself.
278 Q: Will it be possible to use the CLI features without using bytecodes
281 A: Yes. The CLI engine will be made available as a shared library.
282 The garbage collection engine, the threading abstraction, the
283 object system, the dynamic type code system and the JIT will be
284 available for C developers to integreate with their applications if
287 Q: Will you have new development tools?
289 A: Hopefully Free Software enthusiasts will contribute tools to
290 improve the developer environment. These tools could be developed
291 initially using Microsoft implementation of the CLI and then
292 executed later with Mono.
296 Q: What about using Java? After all there are many languages that
299 A: You can get very good tools for doing Java development on free
300 systems right now. <a href="http://www.redhat.com">Red Hat</a> has
301 contributed a <a href="http://gcc.gnu.org">GCC</a> <a
302 href="http://gcc.gnu.org/java">frontend for Java</a> that can take
303 Java sources or Java byte codes and generate native executables; <a
304 href="http://www.transvirtual.com">Transvirtual</a> has implemented
305 <a href="http://www.kaffe.org">Kaffe</a> a JIT engine for Java;
306 Intel also has a Java VM called <a
307 href="http://www.intel.com/research/mrl/orp">ORP</a>.
309 The JVM is not designed to be a general purpose virtual machine.
310 The Common Intermediate Language (CIL), on the other hand, is
311 designed to be a target for a
312 wide variety of programming languages, and has a set of rules
313 designed to be optimal for JITers.
315 Q: What kind of rules make the Common Intermediate Language useful for
318 A: The main rule is that the stack in the CLI is not a general purpose
319 stack. You are not allowed to use it for other purposes than
320 computing values and passing arguments to functions or return
323 At any given call or return instruction, the types on the stack
324 have to be the same independently of the flow of execution of your
329 Q: Would you allow other classes other than those in the
332 A: Yes. The Microsoft class collection is very big, but it is by no
333 means complete. It would be nice to have a port of `Camel' (the
334 Mail API used by Evolution inspired by Java Mail) for Mono
337 You might also want to look into implementing CORBA for Mono. Not
338 only because it would be useful, but because it sounds like a fun
339 thing to do, given the fact that the CLI is such a type rich
342 For more information on extending Mono, see our <a
343 href="ideas.html">ideas</a> page.
345 ** Mono and portability
347 Q: Will Mono only work on Linux?
349 A: Currently, we are doing our work on Linux-based systems and
350 Windows. We do not expect many Linux-isms in the code, so it
351 should be easy to port Mono to other UNIX variants.
353 Q: What about Mono on non X-based systems?
355 A: Our main intention at Ximian is to be able to develop GNOME
356 applications with Mono, but if you are interested in providing a
357 port of the Winform classes to other platforms (frame buffer or
358 MacOS X for example), we would gladly integrate them, as long
359 they are under a Free Software License.
361 ** Reusing existing Code
363 Q: What projects will you reuse or build upon?
365 A: We want to get Mono in the hands of programmers soon. We are
366 interested in reusing existing open source software.
368 Q: What about Intel's research JIT framework, ORP?
370 A: At this time, we are investigating whether we can use elements of
373 Q: What about using GNU Lightning?
375 A: We are also researching <a
376 href="http://www.gnu.org/software/lightning/lightning.html">GNU
379 ** Ximian and Microsoft
381 Q: Didn't Miguel de Icaza say that `Unix Sucks'?
383 A: Yes, he did, as a catch phrase in his opening remark on the Ottawa
384 Linux Symposium. His talk focused on various ways to improve Unix.
386 There is a paper describing some ways to improve Unix at:
388 <a href="http://primates.ximian.com/~miguel/bongo-bong.html">
389 http://primates.ximian.com/~miguel/bongo-bong.html</a>
391 Q: Didn't Ximian's Miguel work for Microsoft?
393 A: Actually, Nat Friedman (Ximian's co-founder) did work as an
394 intern for Microsoft for one summer but Miguel did not.
396 Q: Did Nat and Miguel meet at Microsoft?
398 A: They met online on the Linux IRC network; They met in person for
399 the first time in 1997.
403 Q: What is the difference between CLR (Common Language Runtime) and
404 CLI (Common Language Infrastructure)?
406 A: CLI is the specification of an execution system. The Microsoft
407 implementation of this specification is named CLR.
409 Unless we come up with our own acronym, we could just call ours
410 also CLR, just because it would do exactly the same thing the
411 Microsoft implementation does.
416 Q: Should someone work on a GCC front-end to C#?
418 A: I would love if someone does, and we would love to help anyone that
419 takes on that task, but we do not have the time or expertise to
420 build a C# compiler with the GCC engine. I find it a lot more fun
421 personally to work on C# on a C# compiler, which has an intrinsic
424 Q: Should someone make a GCC backend that will generate CIL images?
426 A: I would love to see a backend to GCC that generates CIL images. It
427 would provide a ton of free compilers that would generate CIL
428 code. This is something that people would want to look into
429 anyways for Windows interoperation in the future.
431 Q: What about making a front-end to GCC that takes CIL images and
432 generates native code?
434 A: I would love to see this, specially since GCC supports this same
435 feature for Java Byte Codes. You could use the metadata library
436 from Mono to read the byte codes (ie, this would be your
437 "front-end") and generate the trees that get passed to the
440 Ideally our implementation of the CLI will be available as a shared
441 library that could be linked with your application as its runtime
444 Q: But would this work around the GPL in the GCC compiler and allow
445 people to work on non-free front-ends?
447 A: People can already do this by targeting the JVM byte codes (there
448 are about 130 compilers for various languages that target the JVM).