You should have a look at http://www.mono-project.com/

This is an cross platform implementation of the .NET framework.

Regards,
Lionel Schiepers.

To be honest, if cross platform is a main requirement, I wouldn't do all
this work-around... I would switch to Java. Then you as a programmer do
not have to worry, if it will run on a certain platform, as Java nearly
runs anywhere... and Java-Applications can be based on SWT and the
Eclipse Platform, which provides already a lot of nice stuff for
applications.

I think, the time of mono & Co will come, but it is not yet that approved...

Additionaly: Just be aware, that you do not exactly know yet, what the
changes with all the new .NET 3.0/winFX stuff will be. You will have to
wait more time until the mono project also has all these implementations
migrated... or might never be able to migrate certain stuff because of
different operating systems.

Using mono or such things is only recommended for small applications,
but on real big projects I would stick to Java or as you proposed to C++
and do only the GUI stuff in .NET for Windows, in Java for Linux and Mac...

Markus

Janiv,

Forget it than with Net. If your requirements ask this and allows you to
spend probably ten times the cost for less than 10% of the desktops, than
let it be and choose something else.

Just my thought,

Cor

Your options for cross-platform C# development today are as follows

Windows:
   MS .NET
   SSCLI
   Mono

MAC:
   SSCLI
   Mono

Linux:
   Mono
   SSCLI (Argueably as it really runs on BSD)

You can develop for the .NET platform on Windows and Mono on Linux and the
MAC, I do that today. Admittedly, we have run into some issues with Mono,
but only in the cases where we are doing some fancy Generics with .Net 2.0.
I have not personally used the SSCLI on anything but Windows, but I have
heard it makes a great reference platform before deploying to .NET or Mono.

Michael Cummings
Magenic Technologies

[Wants to build a Cross-Platform .Net application]

You can build cross-platform .Net code using Mono. We've been shipping
product this way for quite some time.

At Coversant, we started with the SoapBox Framework which is an XMPP SDK.
This Sdk provides a network stack suitable for sending and receiving XMPP
stanza's across a socket. This includes technologies such as TLS (and SSL),
SASL, Compression, and Xml. This framework is fully object oriented, using a
large subset of the .Net framework.

The SoapBox Framework runs just find under Mono. Through Mono our framework
runs just about everywhere: Solaris, Linux, AIX, OSX, and a number of other
platforms. It took a little bit of work to make this happen, but it can be
done. We have a single code-base, with a few (probably less than 20) "#if"
sections that do slightly different things.

Server applications and SDK type applications are a good fit for Mono.
There's some tinkering required, but it's not bad.

GUI applications can also run through Mono, although not quite as well. At
this point, our production GUI stuff is only Win32/Win64 and not Mono.

Some pitfalls:
- Mono debugging stinks. There's no good answer.
- Dump file analysis is a joke, which makes building a true production
system difficult.
- Performance Coutners and other Windows related structures don't exist.
- Use C#, don't use VB. The Mono C# compiler is much more mature than the VB
compiler.

--
Chris Mullins
Coversant, Inc