Great Western Railway, website of the Didcot Railway Centre. Contains descriptions and images of their large collection of mainly ex GWR rolling stock.
The Great Western Archive, for all things GWR, history, rolling stock profiles and drawings, preserved stock and links to other websites.
GWR Modelling, resources for the GWR modeller, including drawings, livery details, kit availability and links to other sites.
Broad Gauge Society,formed to promote research into the 7ft 0¼in gauge railways of Britain in the 19th Century. Resources include data sheets and kits at 7mm and 4mm scales.