Fritz Elfert wrote plptools, heavily based on two other packages:

  - p3nfsd-5.4 by Rudolf Koenig (rfkoenig@immd4.informatik.uni-erlangen.de)
    an nfs daemon for Psion series 3 and 5
  - plp_1_7 by Philip Proudman (phil@proudman51.freeserve.co.uk)

He writes:

 I want to thank both authors for their nice packages and for making
 these available under GPL which makes it possible for me to create
 this package (which of course is distributed under GPL as well).

 I modified and improved Philip's code to support more (nearly all?)
 rfsv32 commands and to gain speed (approx. 4 times) and stability
 (properly reconnects on lost serial link).

 Rudolf's code originally used a homegrown protocol which needs a
 separate program running on the Psion. I changed his code to use the
 socket-based client-code from Philip's rfsv program thus eliminating
 the need for any software beeing run on the Psion. The rfsv code and
 some other stuff went into a lib (both shared and static available).
 I also removed all Psion 3 related stuff, because a) I can't test it
 and b) Psion no longer supported SIBO.

 Support for the RPC mechanism was added in version 0.5. This support
 was only possible because of Alexander Thoukydides' excellent
 documentation: https://thoukydides.github.io/riscos-psifs/plp.html
 Thanks a lot for that.

 Psion 3 support was added by Matt Gumbley (matt@gumbley.demon.co.uk).

 Have fun. -Fritz

Reuben Thomas has maintained plptools since version 0.13. He fixed
many bugs, updated the KDE utilities to work with KDE 3, but finally
removed them with the approach of KDE 4, enhanced plpftp and replaced
the rather flaky plpnfsd with plpfuse. He has kept the build system
working with newer versions of GNU autotools, and gradually cleaned up
the code and simplified the build system.
