what are your project / team task management tools?

As an "R&D Coordinator" my job requires me to coordinate between our company's support (help desk) dept' to QA, & R&D dept' while also developing / solving bugs & tickets myself.

we use various tools to communicate with each other in person discussions, phone, email, open source CRM system (vtiger), bugzilla & CVS (don't judge me, not my fault...)

i was wondering what team project management tools you guys are using I'm looking for a very simple one, open source web ui based for local lan usage only, would love to hear your recommendations!