xacc.ide is a opensource IDE aimed at mainly .NET development. It has a codeeditor written in 100% C# code, which is faster than most commercial offerings.
ClearLisp is a Common Lisp interpreter written in C# with a large library including all of .NET and an extensive object model. Supports IIS and XSP or Apache with mono. Includes sample code of a personal, file based wiki web application.
A script editor (stored as xml) that displays the code in a graphical way. You can code mainly using your mouse. You can also run your script in one click. Easy manipulation of files, IO, mails, loops, directories... 'XS' stands for 'Xml Script'.