plptools is a set of libraries and utilities for enabling Unix systems to communicate with EPOC PDAs such as the Psion 5mx, Psion Revo and Geofox via the PDA's serial link. On Linux, infrared connections are also possible. The following programs are provided:
Users are advised to see if plptools is provided with their system; at the time of writing (early 2008), plptools is packaged in Ubuntu and Debian.
For developers, a shared library encapsulates the high level Psion Link Protocol and thus makes it easy to write applications without extensive knowledge of the protocol itself. A daemon (ncpd) handles the serial connection and provides its services on a local TCP socket.