AppForge: Develop applications for the Symbian Operating System using Visual Basic and AppForge.
EikonWizard for Visual C++ and EPOC: An Eikon GUI creation wizard for VC5++.
LEA Netbook Olten: Tools and programs for the PSION Netbook running on LEA system. In german.
Olaf Flebbe: Perl on EPOC, documentation on the Psion Link Protocol (PLP) and a Psion5 SDK for Linux.
OPL Miscellany: 3lib's hints page for OPL.
OPX List at McAleely.com: A list of OPXs (OPL extensions) for EPOC, Psion and Geofox PDA's.
Software Development Tools for ARM Architecture: Software Development Tools for the ARM Architecture
Symbian Developer: The people behind the EPOC operating system. Symbian's mission is to set the standard for mobile wireless operating systems and to enable a mass market for Wireless Information Devices.
Twiddlebit Software: EPOC and SIBO (Psion) project planning and advanced OPL development tools (Plan, Plan5, OPP, OPPDBG, GPRINTER.OPX).