# CMUCL 21c The CMUCL project is pleased to announce the release of CMUCL 21c. This is a major release which contains numerous enhancements and bug fixes from the 21a release. CMUCL is a free, high performance implementation of the Common Lisp programming language which runs on most major Unix platforms. It mainly conforms to the ANSI Common Lisp standard. CMUCL provides a sophisticated native code compiler; a powerful foreign function interface; an implementation of CLOS, the Common Lisp Object System, which includes multi-methods and a meta-object protocol; a source-level debugger and code profiler; and an Emacs-like editor implemented in Common Lisp. CMUCL is maintained by a team of volunteers collaborating over the Internet, and is mostly in the public domain. ## New in this release: * Known issues: * Feature enhancements * Changes * ASDF 3.3.0 * ANSI compliance fixes: * Bug fixes: * `ENCODE-UNIVERSAL-TIME` accepts dates from 1899 if the final date after accounting for time zones results in a positive value. (See ticket ~~#36~~.) * `CL:SLEEP` no longer gets interrupted (See ticket ~~#26~~.) * Fix some compiler warnings and clean up funny indentation in asin code. * Trac Tickets: * Gitlab tickets: * Ticket ~~#36~~: encode-universal-time signals error * Ticket ~~#26~~: The cmucl that never sleeps * Ticket ~~#40~~: Move heap space location for linux * Ticket ~~#41~~: Report proper process status * Ticket ~~#44~~: Add docstrings for process accessors * Other changes: * Continuous integration added to build and test cmucl on every check-in. This does a build on a Linux system. * Improvements to the PCL implementation of CLOS: * Changes to building procedure: This release is not binary compatible with code compiled using CMUCL 21b; you will need to recompile FASL files. See http://www.cmucl.org or https://gitlab.common-lisp.net/cmucl/cmucl for more information, See https://gitlab.common-lisp.net/cmucl/cmucl/wikis/GettingCmucl for obtaining CMUCL, including sources and binaries. We hope you enjoy using this release of CMUCL!