I've been digging around IronRuby a bit lately, checking out the source, the specs, and writing very minimal code into rbx to see if it works as expected.  Over the next couple weeks I'm going to try and dig a little deeper into IronRuby in an attempt to get a better feel for where it is, what I might be able to use it for, as well as to experiment with some ideas I've had over the last couple months. 

When I first downloaded IronRuby I did so on my Mac in hopes that I'd be able to cruise around the source in TextMate, compile with Mono, and avoid having to fire up a VM whenever I wanted to experiment.  My initial attempts, albiet not very focused, were a failure.  Fortunately within the last week or two I came across Seo Sanghyeon's IronRuby on Mono How to.

The first step is to download and install Mono 1.9.  Once you have Mono installed you need checkout the IronRuby source from RubyForge and then download and apply this patch that Seo created.  Finally run: rake compile mono=1 and assuming everything goes well you'll be greeted with another command prompt which you can use to fire up rbx (aka IronRuby's irb) and begin experimenting.

svn co http://ironruby.rubyforge.org/svn/trunk ironruby
cd ironruby
patch -p0 < patch-mono-r93
rake compile mono=1
mono build/mono_debug/rbx.exe