These are resources for developers of QuickFIX/J, not the developers who use the tool.
SourceForge Project Site
As the SourceForge Subversion documentation states, you'll generally want to checkout the trunk rather than the root of the repository.
Accessing the repository from Eclipse:
There are two Eclipse plugins that can be used to access Subversion repositories. I (Steve Bate) have been using Subclipse, which is provided by the developers of Subversion. It works in a very similar way to the CVS plugin in Eclipse. The other plugin is called Subversive. I haven't used this one but if you've had experience with it, please add your experience to this page.
Jira Issue Tracking
Jira is used for issue/bug tracking and release management. It can be found here.