I am looking for a tool to manage requirements or features for a software development project. It will be used by a small geographically diverse team of 5-10 people to raise, discuss and track requirements. Consequently it will need:Support for multiple usersWeb-basedSupport a hierarchy between requirements, e.g. parent / child relationshipProvide a means for discussing individual requirementsSupport file uploadsCost effective. Ideally free or Some of the project management tools available are overkill or focus on tasks or resource scheduling rather than features / requirements. Does anyone have a solution? 
Tool to manage requirements throughout a software development lifecycle
project management;tools;requirements