Since the release of version 6.0, KookieJar has been distributed under Mozilla Public License (MPL). Full source code is available from the Downloads section. (Borland Delphi 6 is required to compile the latest version)
For the time being, KookieJar 6.0 is the last incarnation of the program. I am not developing it any more, except to fix any outstanding bugs that may be found. The first program I've ever written was a signature manager, and after so many releases and rewrites in four programming languages, I feel it is finally done, and would rather concentrate on other tasks.
Being open-source, KookieJar is open to everyone. Feel free to download the source code, play with it, modify it, and release your own version if you like. Also, you can still submit comments and suggestions: if you come up with something interesting, I may be motivated to return to developing KookieJar once again. Any further details will be announced here; please check this page occasionally.