Lisp on embedded platforms [closed]

Question

Are there any open source Lisp compilers suitable for real-time embedded applications? I.e. with incremental garbage collection, customisable memory handling, small footprint, etc.

Edit:

To clarify, by "compiler" I meant native code, not bytecode interpreter (though the suggested interpreting implementations for microcontrollers are interesting for being a lot smaller than what I thought possible!).