I thought I'd give some props to all the great work out on the internet related to the d20 System. Below is a list of all the various sites I can find that publish the d20 SRD or d20 Modern reference documents. If you know of others, please let me know.
System Reference Documentswww.systemreferencedocuments.org One of the best places to go when your looking for d20 SRD links, they have several hosted copies of the SRD in various formats. Their copy of the Sovelior-Sage version started me upon this quest.www.andargor.com Data from the D&D 3.5 SRD, with full text, in various formats (xml, ms access, ms sql, chm). Includes Epic and Psionic data with the XPH errata.www.d20srd.org The Hypertext d20 SRD (v3.5 d20 System Reference Document) Contains the entire v3.5 d20 System Reference Document and is fully indexed, hyperlinked, searchable, and accessible.www.darkshire.net This is a collection of notes and files related to the various System Reference Documents released under the WotC Open Gaming License.
Modern Reference Documentswww.12tomidnight.com hosts a copy of the d20 Modern rules. (Hasn't been modified in some time, but still)