 | This articlerelies excessively onreferences toprimary sources. Please improve this article by addingsecondary or tertiary sources. Find sources: "CMU Common Lisp" – news ·newspapers ·books ·scholar ·JSTOR(May 2022) (Learn how and when to remove this message) |
| CMUCL | |
|---|---|
| Original author | Carnegie Mellon University |
| Developer | Various |
| Initial release | Early 1980; 46 years ago (1980) |
| Stable release | |
| Operating system | SeveralPOSIX-compliant OSs |
| Platform | Cross-platform |
| Available in | Common Lisp |
| Type | Compiler andruntime |
| License | Public domain |
| Website | cmucl |
| Repository | |
CMUCL is afreeCommon Lisp implementation, originally developed atCarnegie Mellon University.
CMUCL runs on mostUnix-like platforms, includingLinux andBSD; there is an experimentalWindows port as well.Steel Bank Common Lisp is derived from CMUCL. TheScieneer Common Lisp was a commercial derivative from CMUCL.
The earliest implementation predates Common Lisp and was part ofSpice Lisp, around 1980. In 1985 Rob MacLachlan started re-writing the compiler to what would become the Python compiler and CMUCL was ported to Unix workstations such as the IBM PC RT, MIPS and SPARC. Early CMUCL releases did not support Intel's x86 architecture due to a lack of registers. CMUCL strictly separated type-tagged and immediate data types and the garbage collector would rely on knowing that one half of the CPU registers could only hold tagged types and the other half only untagged types. This did not leave enough registers for a Python backend.
After CMU canceled the project (in favor of aDylan implementation using some of CMUCL's compiler base) maintenance has been taken over by a group of volunteers. By 1996 this group was making regular releases on its own infrastructure.
Around the same time a port to Intel's x86 architecture was completed, first running onFreeBSD, laterLinux. The problem of lacking registers was solved by a new conservative garbage collector. This new garbage collector accepts any value of any type in the registers, and treats anything that might be a pointer as a pointer for the purpose of not collecting or moving its target.
