ProjectPanel was developed simply because there wasn't any project management or issue tracking system that could do everything we needed.
We tried and used a lot of various task and bug systems - Bugzilla, Mantis, Trac, Redmine to name a few free ones.
Every one of them was lacking something.
With ProjectPanel we decided to create a "perfect" project management system that would have everyhting we wanted - flexible and powerful task and bug tracking system, possibility for customers to suggest and vote for ideas,
daily reports for our programers to keep track of work, programmers and managers discussions, and much more.
ProjectPanel is used for development in StrategyQuant for over a year, and we are going public with it just now, when everything was well tested and used in production of a big software package.