it would be difficult to share source code what with all the embedded information

It is still just files on the hard drive, most of them plain text. No more difficult than sharing a set of files built with make and gcc.

With VS.Net they have taken a further step forward in this regard, because the files that define how the project hangs together (the project file and the solution file for grouping projects) are XML.

With .Net you could also take a project coded with VS.Net and build it without having access to the VS.Net enviroment, because the compilers for VB.Net, C# and Javascript.Net all come as part of the .Net SDK, which is all "freely" downloadable.

That would require a fair bit of work on someone's part to come up with scripts to build the project though. I wouldn't surprise me if someone hadn't already knocked up a tool to automate this though, as all the info you need to build the project is in the project and solution files.

There is also no reason why you could take the files from a typical VS.Net project and build them on mono (the Linux version of .Net) as long as it only used the bits of the framework that mono has implemented so far.

Of course with configure on Unix you have more flexiblity because you can target more than one build enviroment, but that is because a bunch of people have worked very hard for years to achieve it. Microsoft have never had the inclination to worry about things like that (or even the need to).