What exactly is the D20 sytem? I've seen it on a few websites, and just saw it mentioned on a thread in the books forum, so, wondering... what is it?

<font color = lightgreen>That means the only dice used are d20s. [img]graemlins/petard.gif[/img] </font>

Taken from D20review.com:

The D20 System consists of the core game mechanics of the Dungeons & Dragons 3rd Edition game from Wizards of the Coast. These rules have been pulled together in the D20 System Reference Document, which will be released as an Open Game under the Open Gaming License. This will allow publishers and fans alike to publish games that are compatible with the D20 System. If they desire, they can also use the D20 System Logo, which appears on the core D&D books, to brand their products, as outlined in the D20 System Trademark License. It should be noted that while the Open Gaming License and the D20 System Trademark License have been approved, the release version of the D20 System Reference Document is still a work in progress (parts have been released officially, and parts are still in the process of being reviewed and prepared for release).

Of course, as the owners of the D20 System, WotC can produce D20 System materials as well. They have published a new Star Wars Roleplaying Game that uses the D20 System rules (modified). They are set to publish two more D20 System games: Call of Cthulhu (a one-book deal, licensed from CoC publisher Chaosium) and a Wheel of Time RPG based on the popular fantasy novel series by Robert Jordan.