Threads are a kind of concurrency.

Currently, threads are supported in sbcl under GNU/Linux, cmucl on x86 (on Linux, FreeBSD and OpenBSD), openmcl on OS X and Linux, ecl on all platforms and OS-es including Linux, Windows, *BSD, Solaris, OS X, and in some commercial Common Lisp implementations.

There are also thread compatibility layers.

  • Also, McCLIM provides a thread compatibility layer in the CLIM-SYS package.