Have you checked this one
PHP debugger DBG | Download PHP debugger DBG software for free at SourceForge.net ?

Are you looking for bug tracking like bugzilla.org or one for debugging ?

I personally have always liked bugzilla and TRAC is another one which I like to use a lot if I am looking for a full all around system. It is geared toward the PM side but has fantastic issue tracking and Subversion integration as well.

I'm currently using JIRA from Atlassian, and i like it alot. Has tons of features and suits my needs well. I can even use it as a PITS (public issue tracking system) where i can give public access to people who want to monitor progress for certain issues. Its only $10 for your first 10 users, so i recommend it if your willing to pay $10 and will have less than 10 people using the system.

I didn't personally try it, but you may want to check zoho's bug tracking, it's free for personal use.

https://www.zoho.com/