Mac App Store - Clozure CL

In the 1980s Common Lisp was often user for artificial intelligence applications. It is just a very powerful and expressive dynamic programming language with the most advanced system for object-oriented programming ever devised. It also makes it easy for a programmer to design a new extension to the language for a special purpose (a "domain specific language") and then write a small compiler that translates that language at compile time. Ruby and Python were inspired by lisp, and if you use one of those languages, you will immediately see the resemblance.

Computers have gotten quite a bit faster and have much more memory than the 1980s. Back them many programmers chose C or C++ because they had to eek out every bit of performance with small disks and slow processors. Common Lisp implementations, like Clozure CL, include ways of adding (optional) type declarations so the complier can produce run-time code that is nearly as fast as C. With Python or Ruby you are limited by the speed of the application. With CL and a little work you can make your programs quite efficient.

The Clozure CL development environment is a joy to work with. Without a lot of annoying pop-ups it gently reminds you of the arguments of any function as you type it in, and there are nice tools for finding functions and classes by name and inspecting even complex data structures. (No syntax highlighting as yet, but I am sure they will add that.) Like other dynamic languages, you can change small parts of your program and your changes are instantly integrated into the running application without having to re-compile the whole thing. Because it is the product of a long heritage of excellent lisp programming environments (the first IDEs), it is quite solid and well thought out.

If you are interested in Common Lisp I would recommend getting a book such as Practical Common Lisp by Peter Seibel (2005) or Land of Lisp by Conrad Barski (2011) and downloading this program. The world has caught up to Common Lisp, and it no longer seems more complex or more resource intensive than the languages and systems we use every day. It is not at all hard to learn, and you will discover quite a bit in the process of learning.

Really great way to get started with CL on OSX. I just started today to try CL for some web programming (yes lisp is great for web stuff too) and Clozure is simply the best to get up and running soon. It comes with a complete IDE so no need to use EMACS which, by itself, is a great plus.