Where is the source code for J?

or: why isn't J licensed under the GPL (or other open source license)?

J software is a commercial venture. Part of J Software's revenue stream is selling the source code to J (footnote 0). Consequently, giving away the source to J would decrease J Software's revenue.

Besides, not all endeavors need be collaborative. How many names are listed on the plaque below your favorite piece of art?

That said, however: the Dictionary of J is free to everyone, and is the abstract, Platonically ideal, J. The implementation is a detail (hence the title of the paper "An Implementation of J"). If you'd like an open source J, just translate the English of the DoJ into machine compilable code. If you need a seed, the source for an early version of J is available.

#0 The source is usually sold to corporate J users with a large install base. The source code provides these large users the confidence that they may continue their J-based business, should J Software (or their relationship with J Software) disappear.

It is many years since the source was freely available, at least prior to 1995, and the language has changed considerably since then. Also, please note that this page is not an "official" statement of Jsoftware policy on source. For that, see source. -- ChrisBurke 2005-11-07 05:46:10