Clasp

Clasp is a new Common Lisp implementation that seamlessly interoperates with C++ libraries and programs using LLVM for compilation to native code. This allows Clasp to take advantage of a vast array of preexisting libraries and programs, such as out of the scientific computing ecosystem. Embedding them in a Common Lisp environment allows you to make use of rapid prototyping, incremental development, and other capabilities that make it a powerful language.

Clasp supports SLIME, ASDF, and Quicklisp. The usual language extensions, such as CFFI, Bordeaux-Threads, and Unicode characters are supported as well.