OpenJ is not very actively maintained. Please see: https://www.jsoftware.com/source.htm and https://github.com/iocane/unbox for alternatives.
From [jsoftware.com] jsw
J is a modern, high-level, general-purpose, high-performance programming language. J is portable and runs on Windows, Unix, Mac, and PocketPC handhelds, both as a GUI and in a console. True 64-bit J systems are available for XP64 or Linux64, on AMD64 or Intel EM64T platforms. J systems can be installed and distributed for free.
Date: Sun, 6 Mar 2011 11:12:31 -0500 From: Eric Iverson <[email protected]> To: Programming forum <[email protected]> Subject: [Jprogramming] J Source under GPL J Source is now available under GPL version 3. If interested you will probably want to join the new source forum. See the Source page at the web site for info on getting the source. J Source discussions should take place in the source forum. ---------------------------------------------------------------------- For information about J forums see https://www.jsoftware.com/forums.htm