This is a personal pick of the most interesting projects, tools, libraries and articles that popped-up in Common Lisp land in the last two years.

Newcomers might not realize how the Common Lisp ecosystem, though stable in many ways, actually evolves, sharpens, tries new solutions, proposes new tools, ships new libraries, revives projects. And everyone might enjoy a refresher.

Here’s my previous overview for 2022.

The same warnings hold: I picked the most important links, in my view, but this list is by no means a compilation of all new CL projects or articles published on the topic. Look for yourself on Reddit, Quicklisp releases, GitHub, and use your favourite search engine.

There are too many great news and achievements to pick 3. I love what’s happening around SBCL (and ECL, and Clozure’s revival), I love everything that got included into Lem and the work on all other editors, I love the webviews and I love the scripting tools that are emerging. What are your top picks?

OK, there’s a news I want to put at the forefront: HackerNews now runs on top of SBCL ;)

If you are discovering the ecosystem, my recommendaton is to not miss these two resources:

  • Awesome-cl - a curated list of libraries (there might be more than you think)
    • if you are looking for a list of recommended libraries on each topic, look here.
  • the CL Cookbook

Now let’s dive in and thanks to everyone involved.

The OpusModus music composition software.

Table of Contents

Community

We could start with some reddit stats: 2025 - a New Year for an old programming language! (numbers are up).

The ELS team kept organizing the conference. We have a date and place for 2025: European Lisp Symposium 2025 in Zürich, May 19⁄20

We saw new and regular Lisp Ireland meetups.

Here’s one of their videos: Lisp Ireland, February 2024 Meetup - Lisp & Hardware Verification with ACL2

@djha-skin ran a survey, which is not an established practice in the community, and analysed the results: Common Lisp Community Survey 2024 Results .

@shinmera (Yukari), the author of many useful libraries and an active member of the ELS, and even the host of the next one, opened a Patreon. “If you’d like to help me continue my full-time open source Lisp work, please consider supporting me.”. Sponsoring Yukari is money well spent. She is on GH sponsors and ko-fi too.

The community is on reddit, Discord, Mastodon, LinkedIn… and also on XMPP.

Documentation

The CL Cookbook is a collaborative resource with new contributors each year: new Cookbook EPUB and PDF release: 2025-01.

We got a great contribution: Cookbook: Building Dynamic Libraries with SBCL-Librarian · by em7

PAIP is a classic, now available on the web: Peter Norvig: Paradigms of Artificial Intelligence Programming, Case Studies in Common Lisp (web version).

New resource: Web Apps in Lisp: Know-how: I wanted a resource specialized for web development in Common Lisp. I mean to continuously extend it from now on.

I’ll include a couple general videos in this section. More videos and more documentation improvements are to be found in their respective sections.

FreeCodeCamp released an extensive Common Lisp course on Youtube: Lisp Programming Language – Full Course for Beginners - freeCodeCamp.org - Youtube.

David Botton of CLOG fame released more beginner material, among which Common Lisp - The Tutorial - Fast, Fun and Practical (with CLOG).

I carry on the work on my Common Lisp course in videos, on the Udemy platform. Lately, I worked on a CLOS tutorial: I published 9 videos (1h 22min) on my course. You’ll know enough to read the sources of Hunchentoot or the Kandria game 🎥 comments. The course is comprised of more than 7 hours of short videos, with a code first approach, divided in 9 chapters. We see some basics but we quickly dive into more advanced Common Lisp topics. You can learn more about it here on GitHub. Students can send me an email for a free link.

Here’s the feedback of redditors:

I can vouch for the Udemy course. From the very first lesson, just firing up the REPL and Emacs/SLIME I was taught something new. It’s a great course.

fuzzmonkey35, January 2025 (reddit)

It is an amazing tutorial. What is really strange is I thought CLOS was complicated. I guess it can be but Vincent is amazing at explaining everything and demystifying it.

intergallactic_llama, January 2025 (reddit)

;)

Implementations

Great times for Common Lisp implementations.

SBCL

SBCL ships monthly releases. You really should look at and appreciate all the activity and the continous improvements.

One noticeable addition: its new garbage collector. SBCL: merge of the mark-region GC.

More improvements include:

  • “the mark-region parallel garbage collector can be enabled on arm64. (Thanks to Hayley Patton)”,
  • new contrib module sb-perf, “a performance-analysing tool for Linux. (thanks to Luke Gorrie and Philipp Marek)”
  • support for cross-compiling the system to Android has been added (thanks to Gleefre)
  • “support for memory allocation arenas is now available on the arm64 platform.”
  • haiku support
  • sb-simd improvements

More good stuff with SBCL:

SBCL on the Nintendo Switch

There are open bounties to improve SBCL:

ABCL

New release: ABCL 1.9.1 “never use a dot oh”: CFFI compatibilities, Java virtual threads, ASDF 3.3.6, fixed loading of Fricas0 and Maxima…

New release ABCL 1.9.2.

New tool: Announcing the First Release of abcl-memory-compiler - Now Available!

CCL

Clozure was a bit active, but rather dormant.

Great news: Clozure is back

Clozure CL 1.13 released.

Allegro

Allegro Common Lisp 11.0 from Franz Inc.

LispWorks

I didn’t spot a patch release (they had a major release in 2022), so let’s link to a discussion: is LispWorks worth it? you might learn some things about LW’s feature set.

ECL

Embeddable, targetting WASM… is it the future?

CLASP

CLASP targets C++ on LLVM.

Release: Clasp v2.5.0

They realeased Clasp v2.7.0 in January, 2025.

For context:

New implementations

Historical: Medley Interlisp

We can run the Medley Interlisp Lisp machine in a browser O_o The work achieved by this group is phenomenal, look:

I suggest to follow @interlisp@fosstodon.org on Mastodon.

Companies and jobs

Yes, some companies still choose Common Lisp today, and some hire with a public job posting.

It’s of course the visible top of the iceberg. If you dream of a Lisp job, I suggest to be active and make yourself visible, you might be contacted by someone without a proper job announce. This could be for an open-source project with funding (happened to me), for a university, etc.

We knew these companies since awesome-lisp-companies -it’s only a list of companies we know about, nothing offical. Additions welcome.

Discussions on the topic:

Projects

Editors

Please check out the Cookbook: editors for a list of good editors for Common Lisp. You migth be surprised.

Let’s highlight a new editor in town: Neomacs: Structural Lisp IDE/computing environment . Mariano integrated it in his moldable web desktop: Integrating Neomacs into my CLOG-powered desktop.

About Emacs

About VSCode

About Lem and Rooms pair programming environment

  • Lem 2.0.0 released
    • released in May 2023, this version added the SDL2 frontend, adding mouse support, graphic capabilities, and Windows support.
    • it brought the possibility to draw images and shapes at any location on a buffer or window.
    • addition of many base16 color themes (180), by @lukpank.
  • Lem 2.1.0 released, with many new contributors. Lem 2.0 definitely caught the eyes of many developers IMO.
    • this is when Lem got its website: https://lem-project.github.io/
    • @sasanidas worked on supporting other implementations: “ECL and CCL should work fairly well”, “ABCL and Clasp are still work in progress, working but with minor bugs.”.
    • I added project-aware commands, find-file-recursively
    • @cxxxr added (among everything else) great Lisp mode additions (just look at the release notes and the screenshots)
    • added a sidebar / filer
    • and much more. Just look at the release.
  • then came out Lem 2.2.0
    • the release notes are less organized ;)
    • added libvterm integration
    • this is when I added the interactive git mode.

Unfortunately these latest releases do not ship a readily usable executable. But the installation recipes have been greatly simplified and use Qlot instead of Roswell. There’s a one-liner shell command to install Lem on Unixes.

Lem’s creator cxxxr is now on GitHub sponsors.

He is also working on Rooms, aka Lem on the cloud: it’s a Lem-based “pair programming environment where you can share your coding sessions”. Only the client is open-source, so far at least.

Demo: https://www.youtube.com/watch?v=IMN7feOQOak

Those are the Lem related articles that popped up:

Lem's Legit Git interface.

About LispWorks

About the Jetbrains plugin

About Jupyter

Other tools

Coalton

I found Coalton-related projects:

E. Fukamachi added Coalton support for Lem: https://lem-project.github.io/modes/coalton-lang/. This adds completion, syntax highlighting, interactive compilation and more inside “coalton-toplevel” forms.

Package managers

Quicklisp had a one year hiatus, because it relies on one man. It finally got an update after 1 year: Quicklisp libraries were updated 2024-10-12. Despite a call for collaboration, we don’t really know how we can help.

But Quicklisp isn’t the only library manager anymore.

Also:

Gamedev

The Kandria game was released: https://kandria.com/

If you are into game dev, this is a paper you cannot miss: Kandria: experience report, presented at the ELS 2023.

Great articles:

and more:

I almost forgot the Lisp Game Jams and the new cool little games. For example: Nano Towers

a simple tower defense game written in Common Lisp with the EON framework based on Raylib, submitted for the Spring Lisp Game Jam 2024.

Links to the jams:

GUI

Many solutions exist. Disclaimer: the perfect GUI library doesn’t exist. Please see the Cookbook/gui and awesome-cl. Also don’t miss the web views available today.

releases:

As always, we might not highlight the work achieved on existing libraries that didn’t get a proper announce. There are more GUI libraries for CL.

demos:

Web

CLOG appeared in 2022 and is kicking. Its API has been stable for 4 years.

You know Hacker News, the website, right? Hacker News now runs on top of SBCL

HN runs on top of Arc, the language. Arc was implemented on top of Racket (-> MzScheme). A new, faster / more efficient, implementation of Arc in SBCL was in the works by a Hacker News site maintainer for some time: called Clarc. Its source code has not been published. Since [late september, 2024], the official Hacker News site runs using Clarc and SBCL.

Here’s (again) my new resource for web development in Common Lisp: Web Apps in Lisp: Know-how.

Now the links:

  • CLOG CLOG 2.0 - Now with a complete Common Lisp IDE and GUI Builder (with or w/o emacs)
  • CLOG OS shell
CLOG shell

Projects built with CLOG:

moldable desktop

Weblocks (continued in the Reblocks project):

More:

Articles:

videos:

libraries:

The web views I mentioned: Electron is a thing, but today we have bindings to webview.h and webUI:

More libraries

Data structures:

Language extensions, core libraries:

Iteration:

Developer tools:

Threads, actors:

Documentation builders:

Databases:

relational database and first order logic:

Numerical and scientific:

Plotting:

Bindings and interfaces:

Serialization:

Date and time:

Utilities:

Bindings and interfaces to other software:

Networking:

Scripting

(I love what’s being done here)

Software releases

Other articles

Videos

Demos:

Web:

More from the ELS (see their Youtube channel):

Learning:

Aaaand that’s it for the tour of the last couple years. Tell me if I missed something. I’ll keep updating this post for a few days.

Happy lisping and show us what you build!