comlain
 - A work tracking system. 
PTS
 - is a problem tracking package based around X and the Athena widgets 
RUST
 - Problem/Work tracking package which can handle multiple mailing lists. 
TRS2 - Trouble Report System
 - This is a set of Bourne shell scrips and C programs intended to maintain a database of trouble reports. 
The Wesleyan Student Net
 - RT is a request tracking package based on the "user sends mail to a group of people to report a problem which is then tracked and dealt with" paradigm.  RT is written in perl5 with a mySQL backend and has CLI and Web interfaces. It's free. 
WebTTS
 - WebTTS - A WWW-based trouble ticketing system written in Perl 5 and designed with ease of use and an Internet-oriented environment in mind, with a backend that uses MySQL.