I didn't really think much from the product description. But after visiting the website I can say that the features are really amazing. For anybody who isn't sure of the value, here a list:

Multiple projects support
Flexible role based access control
Flexible issue tracking system
Gantt chart and calendar
News, documents & files management
Feeds & email notifications
Per project wiki
Per project forums
Time tracking
Custom fields for issues, time-entries, projects and users
SCM integration (SVN, CVS, Git, Mercurial and Bazaar)
Issue creation via email
Multiple LDAP authentication support
User self-registration support
Multilanguage support
Multiple databases support

It's also worth noting that the product is open sourced under GNU General Public License v2 (GPL) The websites looks like it was old 10 years ago. So little bit of polish in more surface level things can go a long way.