There seems to be some confusion about IronLisp, so I will try make it clear. Feel free to ask, if unsure.
1. IronLisp is not a replacement for LSharp, it shares common ideas.
2. The author of LSharp is NOT the author of IronLisp (although I wouldnt mind getting Rob on the team:)).
3. It is called IronLisp (as is IronRuby and IronPython, I assume) as it is targeted for the Silverlight core (iron/silver/metals, get it?).
4. As with IronRuby, the current state of the code is ‘very alpha’, and it doesnt even include a readme.txt and should be regarded as WIP (work-in-progress).
5. I am still learning the in’s and out’s of the DLR (which doesnt have much documentation yet), and this was my 1st attempt at using it for the purpose of constructing a (scripting) language. I have already seen places where I could have (and will probably in the future) done things better.