To fix errors or add functionality just pull the source from our git repository. You can login with your github or twitter authorizations.
For tickets we provide a jira server, too. You can add feature requests, error reports or vulnerabilities to it.
For the coding style of new source, please keep the current style like braces on new lines, not the dangling ones. New code or functianality must include matching unit tests. Those are added manually into testlink.