I have experience on many. team working have to install on of them.
here let me introduce some. those are good ones.
1.mantis is http://www.mantisbt.org/ a free popular web-based bugtracking system. it is written in the php
scripting language and works with mysql ms sql and postgreSql database and a webserver. on windows linux
only have english version.
2. redmine is a flexible project management web application. written using Ruby on Rails framework. it it
cross-platform and cross-database. http://www.redmine.org/
there are available Chinese and many other versions. working on mysql
3. xplanner is a project planning and tracking tool for eXtreme Programming (xp) teams. using java language on
mysql and spring hibernate (O/RM). tomcat server. all are open source free of charge. http://www.xplanner.org/
4. Jira the same as number 3. but not free. very popular in the programming team.