Steve Jackson Games (SJG) maintains a massive digital catalog of 3rd Edition materials, primarily through their Warehouse 23 storefront and DriveThruRPG .
Adventures like Caravan to Ein Arris are available as free downloads specifically for the 3rd Edition ruleset. Digital Format Utility Steve Jackson Games: New And Upcoming Releases
Rules-heavy supplements like Compendium I (Character Creation) and Compendium II (Combat and Campaigns) are also available digitally. Free Digital Resources
Many 3rd Edition supplements—including genre worldbooks like GURPS Japan and GURPS Espionage —have been converted into digital reprints known as the e23 project .