we have just released a 2nd alpha release of SuperTuxKart 0.7. This version has a lot of improvements and bug fixes, more tracks, some new icons and animations. It is still pretty much work in progress, and we would love to get some feedback - e.g. does it work for you, performance, do you like the new icon style or prefer the old one, bug reports etc. Note that due to the missing tracks GPs and challenges will not work, and you will get a lot of warnings/error messages printed - so please don't report issues related to challenges or GP not working ;)
We would also hope that people could help us to port more tracks - it's not that much work, and would help us to get SuperTuxKart back to where it was, especially getting the challenges and GPs back. Also more icons would be nice - and of course always more tracks.
Downloads can be found at sourceforge : https://sourceforge.net/projects/supertuxkart/