Recently I wanted to play around with LISP again (as a way to relax!) and naturally I started looking for IDEs. Java has contributed many things to computer science, but surely one of its most important side effects of it has been the insertion into the popular consciousness of advanced IDEs, IntelliJ IDEA being at the front of this, closely followed by Eclipse and Netbeans.

Interestingly enough, even though LISP has deep roots in the academic community and has been around for decades, the best-known IDEs for LISP out there are not only closed-source, but also commercial, with hefty price tags. Some of the best-known are Allegro Common Lisp and LispWorks. Some of them don’t even offer versions that you can download without contacting sales reps! These companies are apparently living in 1994 or thereabouts. Most of them are Crippleware – they work only for a limited amount of time, or expire, or even generate executables that exit after a while. The fact that their websites also look like something out of 1994 is another clue as to the cluelessness of these companies. It was pretty depressing, really. And no, I don’t like Emacs. Sorry. (You may wonder how on earth I can like LISP but not Emacs… well, I guess the Universe is full of mysteries :)).

Then today I found CUSP, a LISP plugin for Eclipse. Awesome! It’s free, maintained. It supports autocompletion and Macros, and works well. Highly recommended. I can now proceed with LISP hacking in peace. :)

PS: the reasons for playing with LISP (or even trying to do something serious with it) are many, but they are hard to understand if you’ve never used it before. At a minimum, it’s a great way to exercise the brain. LISP, after FORTRAN, is the second-oldest high-level programming language (dating back to 1958–it will be 50 years old next year!), and there are good reasons for both having such staying power. If you’ve never programmed in LISP, you should give it a try – it will blow you away. :)

PPS: I forgot to mention it, but the LISP I use is Steel Bank Common Lisp which seems to be the best out there.

Update: Colm O Mahony just wrote over email to tell me that he tried SBCL 1.0.6 (the latest SBCL version) on top of the older version which comes bundled in CUSP. I tried it as well and it works fine. Thanks Colm! it seems to work fine.