Allegra is the info-bot running on the #Ada channel of the freenode IRC network.
See the file "doc/allegra.html" for tips on building the code. The current snapshot source bundle is version 1.1r144. To build Allegra from source, you also need NAIL, a small infrastructure library containing some routines that previously were distributed as part of the main Allegra package.
Two historical pages related to Allegra's development are:
Allegra was converted from LP to "flat" source during her development, though not without a large measure of regret. There were reasons, and perhaps someday she'll be converted back.