I am currently working on a new language design in the Lisp family, which I am calling 'Thelema'. It is intended to be a multi-paradigm language which is related loosely to Scheme and, to a lesser extent, Common Lisp, but with modern concepts such as package management, support for object oriented design, and an extensive library system.
The current design sketch can be found on its Github repo, where I am (slowly) working on codifying the design and eventually impementing it.
Note that I am not soliciting collaborators (though I wouldn't turn one down out of hand, either). I am hoping to get some eyes on the language design and opinions about it, in the hope that I can find places where it isn't clear or where I have ideas which are unlikely to work. At this point, it is still quite some way away from implementation, though I would like to begin working on a sub-set compiler in the new year.