CLISP is a portable ANSI Common Lisp implementation and development environment by Bruno Haible. Interpreter, compiler, debugger, CLOS, MOP, FFI, Unicode, sockets, CLX. UI in English, German, French, Spanish, Dutch, Russian, and Danish.
Lamp is a Unix-like environment that runs in a single process (via threads) on traditional Mac OS, including standard I/O, vfork/exec, a shell, perl, sockets, virtual fs with /dev and /proc, signals, and ptrace(). Runs on 68K/PPC, and on OS X as Carbon.