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Clozure CL vs Steel Bank Common Lisp: catalog facts
Clozure CL	Steel Bank Common Lisp
Best for: Common Lisp programmers who want a mature, fast-compiling implementation	Best for: Common Lisp developers who want a fast native-code compiler
Free Free and open source under the Apache License 2.0.	Free Free and open source under a permissive licence.
Windows, macOS, Linux, Command line	Windows, macOS, Linux, Command line
Fast compilation speed Native threads and a generational compacting garbage collector All 4 strengths for Clozure CL Fast compilation speed Native threads and a generational compacting garbage collector Convenient foreign-function interface Runs on Windows, macOS, Linux, FreeBSD and illumos	Compiles Common Lisp to fast native code Built-in debugger, profiler and coverage tool All 4 strengths for Steel Bank Common Lisp Compiles Common Lisp to fast native code Built-in debugger, profiler and coverage tool Regular releases Runs on Linux, BSDs, macOS, Solaris and Windows
macOS support covers x86-64 only Community-maintained with a small contributor base	Command-line environment; editor integration comes from tools such as Emacs and SLIME Platform support varies, so check the download page
Downloadable app	Downloadable app
Open source	Open source
License: Apache-2.0	License: Public domain, MIT and BSD-style
No account needed	No account needed
Offline features available	Offline features available
Official website Full listing and sources Sources for Clozure CL ccl.clozure.com Catalog checked October 2, 2026	Official website Full listing and sources Sources for Steel Bank Common Lisp sbcl.org Catalog checked October 1, 2026

“Not stated” means we have not confirmed it. Features can vary by device and plan.