Opensource Helpdesk software for small companies?

Nocts writes: "I'm currently working for a moderately sized company that manages a large portion of its internal help desk questions through a Jabber-based chat room. What we're looking for instead is an Opensource, preferably web-based solution that will give us the ability to have floor representatives queue questions and concerns in a similar fashion to BugTraq, directed at the help desk. Email capability would be preferred for elaboration of specific issues but the more we can centralize everything into the queued system the better. Any recommendations and experiences?

Just about any language is doable since I have the ability to configure and upgrade our servers and we're looking at about a user base of 100 people, with around 5-10 questions a minute."