There are three versions of the Uresia worldbook. In terms of setting-information, all three are mutually compatible. Here's a quick rundown for those interested in Uresia but puzzled by the whole multiple-incarnations thing:

• Uresia: Grave of Heaven (2003): Guardians of Order published the original edition of Uresia in February of 2003 as a supplement to Big Eyes, Small Mouth 2nd Edition, the result of long work, delays and development (beginning July of 2000). The original worldbook includes stats and character-creation information specific to BESM2, and it's a groovy little digest-sized worldbook that fits in your coat pocket. GoO also made this edition available in electronic form for a while (2004-2005).
• Uresia d20 (2004): The original book did well enough to justify porting it to one of GoO's other game-systems, their hybrid of BESM with Wizards of the Coasts' d20 System used for Dungeons & Dragons 3.x. GoO courteously invited me to develop the d20 adaptation, but I'm no d20 scholar, so I passed on it and just pestered them about the cover, instead (it ended up with a beautiful cover, by the talented Niko Geyer). Decorated d20 veteran Ian Sturrock did officer work handling the system-conversions, and Uresia d20 is, in terms of setting content, virtually identical to the original, with only the BESM stats replaced. The only other differences are a few artwork alterations, some of Ian's extrapolations on how the "character classes" relate to one another, and one omitted map (a non-critical introduction to the world and the runic alphabet used in the page elements). This edition was also available in digital form (2004-2005).
• Uresia: Grave of Heaven (All-Systems Library Edition, 2012): In the spring of 2005, I approached Guardians of Order asking about buying all the Uresia rights. Mark responded with an offer that suited us both, and on August 31st of that year the material came home, as it were, to Cumberland Games. I took my time developing the Cumberland edition, carefully expanding it and then pruning it again (more than 40,000 words were left on the cutting-room floor, despite the final work being twice that size!) and I'm very proud of it. The All-Systems Edition is (as I like to put it) unencumbered by crunch. Like all other All-Systems titles (including Caravel) this "Designer's Cut" edition is 100% setting and gaming resources, taking advantage of the additional space to provide a few surprises.

Cumberland Games has been publishing Uresia material since the 2001 release of the Temphis Runes and that, along with Uresia Arcana and Caravel, form the beginnings of what I hope will be a game line worth revisiting and campaigning with for years to come. Uresia is a very comfy home for the kind of fantasy gaming I like to write about, and I hope to keep writing about it for as long as I can.

In addition to Uresia 2nd Edition, you can also find new Uresia material here on Blue Lamp Road. Better still, the Uresia fan-community produces some great stuff that appears here and elsewhere on the web.