Over the past two years Tesseract has been under heavy development. In that time, Tesseract has become much more visually advanced compared to Sauerbraten and has been working on features like OpenGL 3 and Occulus Rift support.
After two years of hard work by two developers, the first official Tesseract release has finally shipped! You can see the brief release announcement via this forum post at Tesseract.gg. I've also been in contact with the lead developer and there is benchmark capabilities.