http://yam.20to4.net/
It's got pictures of a homebrew 3D engine built for the DC that looks outstanding, featuring bump mapping and impressive lighting
http://yam.20to4.net/dreamcast/index_old.html


It has instructions for replacing your bios, and what seems to be custom hardware for selecting between bioses.
http://yam.20to4.net/g1_flash/index.html
And even (old, circa 2006 or so) a page detailing the author's work on "KEII" (aka "Katana Engine 2") a software kit to greatly speed up and make easier, homebrew development on DC. (this page is not accessible from the main page?)
http://yam.20to4.net/dreamcast/
And also advanced programming tips for how to efficiently display 3D graphics on the DC. (this page also not accessible from the main page)
http://yam.20to4.net/dreamcast/hints/index.html
Clearly this guy is EXTREMELY knowledgeable about the dreamcast and has a thorough knowledge of the hardware and how to do high level programming for it, even outside of the official tools. Who is this mysterious Yamato (Yam20to4)? Is he still active (most recent links on the main page seem to be from December 2010)? Is anyone familiar with his projects? Were any of them ever released in any way? We need to get him involved again, and/or provide more data on his projects
