The OSVR waffle.io board contains an overview of issues currently in GitHub issue trackers for all OSVR framework projects. It summarizes the issues in a number of lists:
Of course, the issue lists are not all-encompassing: if you've got a contribution you'd like to make, we'd love to see it! Filing an issue on the right project would be a great first step.
Note that in case you can't find the project you're looking for below, you can access a full list of projects in the OSVR organization (note that this link includes a filter to exclude projects forked by OSVR).
The core libraries, applications, and plugins of the OSVR software platform. Includes osvr_reset_yaw, which allows setting '0 heading', osvr_print_tree that exports the path tree and osvr_json_to_c which converts JSON files into C headers
Package for authoring OSVR experiences with Unity.
Integration of OSVR with the Unreal Engine.
Tool for determining distortion parameters of arbitrary HMDs, and a corresponding set of shaders to correct that distortion.