All in One PSA for MSPs, which Unifies client, contact, vendor, asset, license, domain, ssl certificate, password, documentation, file, network and location management with ticketing and billing capabilities, with a client portal on the side.
A simple-to-use and -install issue-tracking system with command-line, web, REST, XML-RPC, and e-mail interfaces. Designed with flexibility in mind - not just another bug tracker.