I am involved with maintaining a fairly large portfolio of .NET applications. Also in the portfolio are legacy applications built on top of other platforms - native C++, ECLIPS Forms, etc.

I have a complex build framework on top of NAnt right now that manages the builds for all of these applications. The build framework uses NAnt to do a number of different things:

• Pull code out of Subversion, as well as create tags in Subversion
• Build the code, using MSBuild for .NET or other compilers for other platforms
• Peek inside AssemblyInfo files to increment version numbers
• Do deletes of certain files that shouldn't be included in builds / releases
• Releases code to deployment folders
• Zips code up for backup purposes
• Deploy Windows services; start and stop them
• Etc.

Most of those things can be done with just NAnt by itself, but we did build a couple of extension tasks for NAnt to do some things that were specific to our environment. Also, most of those processes above are genericized and reused across a lot of our different application build scripts, so that we don't repeat logic. So it is not simple NAnt code, and not simple build scripts. There are dozens of NAnt files that come together to execute a build.

Lately I've been dissatisfied with NAnt for a couple reasons: (1) it's syntax is just awful - programming languages on top of XML are really horrific to maintain, (2) the project seems to have died on the vine; there haven't been a ton of updates lately and it seems like no one is really at the helm. Trying to get it working with .NET 4 has cause some pain points due to this lack of activity.

So, with all of that background out of the way, here's my question. Given some of the things that I want to accomplish based on that list above, and given that I am primarily in a .NET shop, but I also need to build non-.NET projects, is there an alternative to NAnt that I should consider switching to?

Things on my radar include Powershell (with or without psake), MSBuild by itself, and rake. These all have pros and cons. For example, is MSBuild powerful enough? I remember using it years ago and it didn't seem to have as much power as NAnt. Do I really want to have my team learn Ruby just to do builds using rake? Is psake really mature enough of a project to pin my portfolio to? Is Powershell "too close to the metal" and I'll end up having to write my own build library akin to psake to use it on its own?

Are there other tools that I should consider? If you were involved with maintaining a .NET portfolio of significant complexity, what build tool would you be looking at? What does your team currently use?