Alien Arena is powered by the CRX game engine, which is a heavily-modified version of the open-source id Tech 2 engine that's since been largely rewritten to incorporate high-resolution textures, GLSL per-pixel lighting, parallax mapping, light bloom, Open Dynamics Engine physics support, shaders, texture particles, OpenAL, and various other features.
Following last month's release of Alien Arena: Reloaded (v7.60), the developers have spent time improving the performance of the first person shooter game while upping the visual quality too.
In particular, work has been done on improving map rendering and added support for mesh rendering. Below is the email that Max Eliaser, an Alien Arena developer, sent into Phoronix about this recent work.
After the recent release of Alien Arena 7.60, we did not stop working, but immediately got to work on improving our framerates and efficiency. I've been working on map rendering, while our lead developer John Diamond has been working on mesh rendering. This is already starting to pay off. I've attached before-and-after screenshots you can use, showing how we've improved framerates in the last few weeks.He's also provided some before-and-after screenshots to showcase the latest Alien Arena work that will be released in a few months time.
There is definitely more room for improvement, so expect framerates to be even higher by the time we actually release the next version. The new version will probably not be released until a few months from now. However, players can already check out what we've been working on by downloading from our SVN repository at svn://svn.icculus.org/alienarena/trunk and following the compile instructions in the README file. They should be aware that this is unstable and potentially buggy code, but for those players who have previously tried Alien Arena and were unable to get it running smoothly, it's worth trying.
With map rendering and high quality settings, the frame-rate goes from 33 to 56 FPS. With mesh rendering on high, the OpenGL frame-rate goes from 25 to 47 FPS. Lastly, with map rendering on medium quality settings, Alien Arena runs at 120 FPS now instead of 87 FPS.