Simple-to-use/-install issue-tracking system: web, REST, email, CLI
Open source help desk ticketing system
The Free & Popular HESK Web Based Software in Complete Virtual Machine
HelpDEZk is a powerfull software that manages requests/incidents.
Help Desk Software
Issue tracking and team collaboration system
Car Sales Management System, Vehicle Sales Management in Codeigniter
Jnestor is another majordomo in java
Ticket System .NET Open Source (ITS, Issue tracking system)