I'm inspired by Paul Graham's papers on Arc ( http://www.paulgraham.com/arc.html ). I don't agree with everything that Paul says; in particular he says that "Unix won"; from where I'm sitting it seems that Microsoft Windows won. LSharp is my way of playing with Arc and Lisp ideas, and building something useful to me at the same time.

I do lots of development on the Microsoft .NET platform. One thing that seems to be missing is a really good scripting language and experimentation environment. I hope that L Sharp will fill this hole.

Whatever you feel about Microsoft, the .NET Framework is pretty cool. Any new Lisp implementation will only be successful if it can provide a rich, standardised library; the .NET framework could provide that. It gives us interoperability with large amounts of code, as well as credibility in the real world. I hope that Mono will allow L Sharp to run on an variety of platforms.

L Sharp has been developed as part of a Research and Development initiative at Active Web Solutions. I'd like to thank the board of AWS for their generous support.

L Sharp is working pretty well, but the language and tools are still changing. It's mostly being used for experimentation and "throw away" scripts, but people are using it successfully in production environments too.

I presented a paper at the 2nd European LISP and Scheme Workshop, ECOOP 2005. The paper and slides are available here.

I'm also grateful to Patrick Dussud at Microsoft who has experimented with LSharp and provided useful feedback.