Java Psion Link (JPL), is intended to be a cross-platform solution for transferring files between Psion Epoc PDAs (netBook, series 7, 5Mx, revo) and any computer with a serial port and the ability to run java.
For the latest versions and news please check SourceForge.
The source code for JPL is available (under the GPL).
Once you have installed JPL and got it to work you might want to look at this manual.
There is also a brief FAQ.
Most of the information I needed to write JPL has come via these pages:
Added 22/05/2006: For OS X users there is also now an installation video/screencast, hosted on ShowMeDo:
Java Psion Link requires that you have Java and javax.comm installed on your system.
You will also need to ensure you have installed a working serial port USB adapter (see FAQ).
There is a video available, that should walk you through the installation process.
My main development machine is a Mac running OS X, so the OS X version of JPL should usually work very well. However I do not currently have an Intel mac, but installing javax.comm on an Intel mac is possible.
Another project has more information on using javax.comm with Intel macs here:
http://jmri.sourceforge.net/install/MacOSX.html
There is also a guide available, in German, written by Frank
Emmerlich, here.
Kevan Jones has provided a guide (rtf) to getting JPL working on Windows NT. It mainly deals with getting javax.comm installed, as this is the tricky part.
I am happy to hear from you if you have trouble getting Java Psion Link to work. I will try to help you out if I can, but I cannot promise that Java Psion Link will work on your system. I also cannot promise to reply to your email as at times other commitments in my life get in the way.
Development on JPL has basically stopped now (I haven't written any new code for at least two years at this point). Although it is still in "alpha" it is fairly stable and seems to still be useful to a number of people.
If you have any questions feel free to comtact me. I'd also be interested to hear from anyone who might wish to continue developing JPL.