Acorn Electron World - Archive of Acorn Electron games and applications in popular emulator formats along with instructions, articles, magazine scans, hardware information, books and manuals.
ElectrEm - An open source emulator for Mac OS X and Windows. Older versions for DOS and Linux are also available, as is the source code.
Elkulator - A freeware Acorn Electron Emulator for DOS and Windows with source code.
The Stairway To Hell - A collection of Electron games in Universal Emulator Format.
