sayanara(http://sayanara.sourceforge.net/): Conversion of EPOC Agenda and Contacts documents to native GNOME documents. Works on EPOC release 5 devices such as the Psion 5mx, Psion 7 and Netbook.
psi2latex(http://website.lineone.net/~j.ottaway/psi2latex.html) is a C program which converts Psion 5 Word files to LaTeX.
kab2psion(http://web.wanadoo.be/rc.s/kab2psion/index.html) is a small Perl utility which extracts the contents of a KDE addressbook and produces a CSV file which can be imported into the Psion5 data utility.
PsiConv(http://software.frodo.looijaard.name/psiconv/) is a file conversion utility that converts between Psion 5(MX) files and more commonly used Linux file formats. It can read and write Psion Word, TextEd, Sketch, MBM, and Clipart files, and outputs HTML 3.2, HTML 4, ASCII, and almost any graphical format. The libpsiconv library can also read Sheet files for use in other programs. Included is full documentation on several Psion 5(MX) file formats. This information is not available from Psion (it has been reverse-engineered from Psion files), and it's free for anybody to use.
LinPoch(http://linpoch.sf.net/) is a connectivity software suite which makes it possible to communicate with an Epoc 6 device, under Linux. The main goal of LinPoch is to provide connectivity between Epoc 6 devices and Linux / UNIX, but mainly the Nokia 9210 cell phone.
Java Psion Link (JPL)(http://website.lineone.net/~john.montgomery/psionlink/) is intended to be a cross-platform solution for transferring files between Psion Epoc PDAs (netBook, series 7, 5Mx, and revo) and any computer with a serial port and the ability to run Java.
psilin(http://www.medsyn.fr/perso/g.delafond/) connects any Psion to Linux. It makes a Psion become a UNIX terminal, and converts all sorts of files and backups.
PLP-Tools(http://sourceforge.net/projects/plptools/) connect a PSION via NFS and PPP to a Linux box.
If you have been using Psion devices alongside with UNIXish operating systems for a long time, you will probably remember (or even still use ;) the p3nfs software by Rudolf König, which makes basic NFS functionality available on the Psion. The p3nfs(http://www.koeniglich.de/p3nfs.html) has been ressurected by him and has been extended to work on EPOC R6 and specifically on the NOKIA Communicator. While at some point the PLP-Tools(http://sourceforge.net/projects/plptools/) should integrate this functionality, you may use this solution in the meantime.
Nfsc(http://www.koeniglich.de/p3nfs.html) is a VT100 terminal emulator for the Psion Series 3 (i.e. 3/3a/3c/3mx & Sienna) palmtops.
Linux/IR(http://irda.sourceforge.net/) is a project with the goal of implementing the IrDA protocol stack into the Linux kernel. IrDA is a standard for infrared communication between devices such as laptops, printers, PDAs, mobile phones, LAN access points etc.
gtklepin(http://ordiluc.net/gtklepin/) is a notebook that uses the GTK+ toolkit. It has similar functionality to the notebook found on the Psion Revo PDA.
FreeVT(http://www.home.unix-ag.org/nils/freevt.html) is a VT100 emulation software package for the Psion Series 3a handheld computers. It is completely free, i.e. protected under the terms of the GNU Public License (GPL).
psionconf is a small utility for PicoGUI to control various settings under Psion Linux.
Normally development for EPOC devices is done under Windows, since the SDK distributed by SYMBIAN(http://www.symbian.com) is targeted for this platform. Still you might belong to those who prefer to use UNIXish operating systems for program development. If this is the case, this page by KI-AG will tell you how to set up a development environment under Linux.
epocemx(http://epocemx.sourceforge.net) is a collection of tools (including a port of GCC) and libraries which enable building EPOC R5 (ER5) applications under Unix. EPOC R6 (ER6, Symbian OS) is not supported.
GnuPoc(http://www.gnupoc.org/) makes it possible to develop EPOC applications on your GNU/Linux machine. It is using GNU make, Wine and GCC crosscompiler for ARM. Because of the EPOC SDK license we are not allowed to redistribute it, but you can apply the diff if you already have the SDK. The aim of this project is to make a complete EPOC SDK for Linux, any architecture, with full debugging and which is released under GPL.
Linux runs not only on the Psion Series 5 nowaydays, but also on the Series 5mx and the Series 7. see the official website(http://linux-7110.sourceforge.net/) and the Series 7 port(http://www.yipton.demon.co.uk).
This Psion-HOWTO(http://www.tldp.org/HOWTO/Psion-HOWTO.html) describes how to use Psion palmtops with Linux, but does not cover running Linux on a Psion palmtop. See the Linux 7k project (http://linux-7110.sourceforge.net/) for that.
This page(http://fchabaud.free.fr/English/Tricks/Laptop/default.php3?COUNT=1&FILE0=Revo) describes how to make this handheld device dialoguing with a Linux box. It covers both infrared and serial communication.
This is a first attempt at putting Psion's Programmer's Reference(http://www.si.unix-ag.org/docs/psionopl/) onto the Web.
"You've quite possibly never heard of OPL, but once upon a time this wouldn't have been the case. Back before Palm was thought of, OPL was the easy to use development language for Psion EPOC devices, and until events (and indeed Palm) largely overwhelmed Psion, there was quite a thriving community of small developers and enthusiasts using OPL(http://www.theregister.co.uk/content/4/28465.html) ..."
Openpsion(http://www.openpsion.org) (formerly psilinux) is a project to port the unix-like operating system Linux to a group of palmtops produced by Psion, and related machines such as the Geofox One. At present, working linux systems can be installed on any of the Series 5, Series 5MX, Series 5MX-Pro, Revo (Revo+, Mako) machines (NOT the Series 3). Linux on the Series 7/netBook is rudimentarily working.