The Xbox Linux Project website has posted a guide about How to Install SuSE Linux 8 on your Xbox:

"Standard Linux distributions do work on the Xbox, with minor modifications. To run SuSE Linux as a server, you only have to change two lines in the Linux kernel, disable one init script and install two drivers for audio and networking. Having an Xbox that runs as a standalone Linux workstation does not require much more work. This article is a step-by-step tutorial to install SuSE 8 with X-Window on the Xbox."

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