The JEDI Code Library is built upon donations by various individuals. In the documentation for each subroutine or class you will find who the author of that particular code is by looking in the "Quick Info" section. The author's e-mail is not listed there. It is listed in the contributors page elsewhere in this document. Therefore if you really need to contact an author it is possible. However, generically speaking, you should never contact an author regarding code included in this library. There are various reasons for this with the two most prominent being that some authors explicitly requested this and because "author" means different things in different context. Usually "author" means that the described code was donated to the JCL by that individual and included after reformatting and only minor modifications. However, sometimes code was significantly altered, rewritten several times or 'merely' based upon or inspired by code from that individual. Consequently there exist several routines which in no way resemble the original code as it was donated by the "author". Nevertheless, the individual that orginally donated the code is still documented as the author.
In general, if you like some routine very much and it has proven to work correctly: be grateful to the author (in thought, not by sending him or her an e-mail). On the other hand, if some routine turns out to be buggy, incorrect or for whatever reason is not to your liking: complain to me. It was most likely we who screwed it up and introduced those bugs into code that was working perfectly until we got our hands on it! To report bugs, use Project JEDI's Issue Tracker.