Unless you are a developer, you definitely should be using code from the stable branch, not this alpha code.
The Alpha Testing space is a place where some of the potential code branches of Relativty can be found. Because this is all "Alpha" code, it is all very much in development. That means that it still needs a lot of work. It is probably unstable, untested & no release-ready. If you are interested in helping out, get in touch with us on Discord, download some of the code & have a play around with it. You might be the one who makes a massive breakthrough for the project, or who takes us in a completely new direction, or who helps to increase our understanding of how everything works and fits together.
We have several areas that we are working on at the moment, although feel free to start a new one if you have a really interesting concept that needs developing.
Top of the list is our migration from 6DoF to 9DoF. This is a wide ranging project, with lots of different components, so we've had to break it down into different sections.
An introduction to 6Dof, 9Dof, and why they are important.
Different types of sensor boards and chips (page unfinished!).
An MPU-9250 and an Arduino as a 9DoF tracker (version 0.1 of the code)
As the test sensor breakout boards arrive, this page will be updated with the results.
Next, and just as important, is the OpenXR code migration. All of our existing code, both in terms of Arduino tracker sketches and our software drivers, is written to work with OSVR. Alas, OSVR is yesterday's VR standard, and as such is now completely obsolete. The latest standard is OpenXR, and in order to develop our OpenXR compliant drivers as quickly as possible, we are creating OpenHMD drivers for Relativty. This is another huge project, which currently has great tracts of uncharted territory...
The main developer behind this is Anorak