Suggested Programming Projects
These projects are intended for those who feel they would like to make a contribution in the form of free Common Lisp code.

Some of the projects in this list are old or no longer relevant. If you find a project where this is the case please remove it from the list

Library quality

Libraries wanted

Projects related to Common Lisp implementations

  • Add a peephole optimizer phase to sbcl's compiler, and use it for microoptimizations on some sbcl platforms.
  • Add some loop optimizations (such as invariant lifting, common subexpression elimination, ...) to sbcl's compiler.
  • Write a real-time generational SMP-aware garbage collector for SBCL. Contact Robert Strandh for more information.
  • Make CLISP more easily embeddable in other (C) applications.

Development tools

  • Write a Learnable Programming Environment for CL development. See for example Khan Academy environment Learnable Programming, or Chris Granger's LightTable IDE. We'd want that both to promote Lisp amongst youngsters and as a nice Lisp development IDE. Note: the examples are graphical for the quick feed back provided to newbies, but the same tools can also be applied to more "abstract" programs, either thru visualization modules, or just showing textually the state of the variables, etc. Such an environment would also include naturally Debugging Backward in Time. See also Harald Wertz papers on program understanding, etc.
  • Port the Dylan editor Deuce (see CL-Emacs for info) to CL. We need a smaller/simpler/faster editor than Portable Hemlock or CLimacs to compete with GNU Emacs.
  • Port GNU Emacs to run on Common Lisp as a back-end platform. Co-opt the GNU Emacs users. See Emacs to CL Porting Attempts.
  • Enhance Climacs, for example in the areas of redisplay performance or (the lack of) ease of defining new syntaxes. A syntax for C would also be useful.

CLX projects

  • implement transparent (to the user) support for the BIG-REQUESTS X protocol extension. This allows more efficient support for other X extensions such as GLX and RENDER.
  • implement transparent (to the user) support for the XKEYBOARD X extension; the protocol specification (dated 1994) provides enough information to how to do this. This would allow libraries such as McCLIM to provide better keyboard handling in their applications, dealing with confusions over whether modifiers such as the shift key are significant.

X11 projects

  • Work on the zen X11 server. Make it run on Wayland with hardware acceleration.

McCLIM projects

See also the McCLIM project page.

  • Create a debugger pane and/or a debugger application to work with the Listener and other CLIM applications. This is partially done. Contact Robert Strandh for more information.
  • Add "modern" panes and gadgets as extensions to McCLIM.


  • Make it possible to use Common Lisp as an extension language for Texmacs. (a few weeks).
  • Terminal emulator for Common Lisp. Port either Paddy Mullen's rxvt-js or the suckless st terminal emulator to CL. Use this to replace xterm on your *nix desktop, add terminal emulation to McCLIM, terminal emulation modes to Climacs and Portable Hemlock, and eventually as the terminal emulator in a Lisp OS.
  • Port Tony Garnock-Jones' Racket-SSH to Common Lisp. Get a CL SSH client so you can talk to *nix servers securely, an SSH server so Lisp processes can talk to each other securely. Combine with terminal emulator above to get rid of your OpenSSH client. Will be needed for a Lisp OS.

Closure web browser extensions

  • Integrate CL-JavaScript into the Closure web browser.
  • Once Closure has JavaScript support, adapt rxvt-js (a JavaScript/DHTML port of urxvt) to run as a stand-alone native application (using Closure as a library), to serve as a replacement for xterm/rxvt.
  • Add HTML5 support to the Closure web browser.

Documentation projects

  • Write a user manual for CLIM/McCLIM, including in particular a Getting Started manual.
  • Write a manual that explains the internals of SBCL.
  • Convert the user's manual for Hemlock from Scribe to Texinfo.
  • Convert the command implementer's guide for Hemlock from Scribe to Texinfo.
  • Convert section 2 of AMOP to Texinfo, TeX sources are available from
  • Convert the final ANSI draft spec to Texinfo, obtaining also official clarification on its copyright status (a month). What's wrong with dpans2texi? *blush* -- I'd totally forgotten about it. Clarification on the copyright status of dpANS would still be good, though. Situation is murky.

    The situation with the draft spec is probably not improvable - there were too many authors and it was too long ago. Of course, given that the drafts have been publicly and freely downloadable for ten years, and Franz has a copy of dpANS2 on their website with a copyright notice concerning the presentation... The only other thing to do would be to try to track down all the authors/companies and get a statement from each of them. That's going to be tough, and even if they could all be located how does one sort out who wrote what? Also, even if someone had an objection to their part being free how would they demonstrate they are in fact the author of that part? With no copyright notices on the draft spec itself to identify authors of specific parts, the only way to be sure would be to identify the content in some other published work. Not that anyone would be likely to lie, granted...