I've taken a branch of the etr svn trunk (not the releases) and pushed it up to GitHub: https://github.com/RKSimon/extremetuxracer
This is the first time that I've used git + GitHub on a project open to others, so please be patient if you make any pull requests etc. I noticed that someone has already forked it and seems to be working on psp homebrew support.
At the moment my patches are some minor performance fixes and I've rewritten the Makefile + headers to get it building on Linux/OSX/MinGW - you just have to type make now, no more commenting out code for your platform (assuming that your SDL libs are in sane places!). The OSX build assumes that you are using SDL frameworks.
I'm also working on tidying up the GL code so that its more modern and will make the GLES conversion easier in a couple of weeks time (more vertex pointers, less glBegin/glEnd etc.). RS still haven't delivered my pi yet, so all the arm work is being done on my pandaboard - and being selective on the gl functions you use can make a big difference to fps on the omap gl driver. I've been putting off the egl work until I can better see what is happening with SDL 1.3/2.0 - I was hoping that the promised gles support would just work, but now I'm not too sure - its on my list of things to look at!
Other things I'm working on include better clang support / windows native builds (and in general make the code more cross platform friendly), reduce compiler warnings (I intend to add -Werror sometime soon), and start running the code through clang static analyzer.
Is it an issue for anyone that I started from the trunk instead of an existing release? I'm happy to help work with anyone who can manage to get the existing etr website + sf project working again, but until then I'm going to carry on pushing my fixes to GitHub.