My operating system of choice is
Debian GNU/Linux, a powerful and most of all
free Unix system. Some years ago I decided to contribute more actively to this
project and applied to become a developer.
I'm running the Debian unstable (sid) distribution on my workstation, which
is amazingly stable, apart from the occasional dist-upgrade breakage... ;)
I have been a co-developer of the P2P (peer-to-peer) framework and client
which has quite a lot of features, (mostly provided by a large number of plugins)
and which - being written in Java - runs on pretty much every platform.
Unfortunately development came to a grinding halt when my former co-developers
left the project, since I lack both the time (and for some parts of the codebase also
the skill) to do any further substanstial development.
Have a look at http://xnap.org if you want to know more or would like to contribute.
Recently I've written some ldap scripts for a school where I've taught computing.
They might be helpful if you have to set up large numbers of ldap accounts
in a batch, following a fixed scheme. You can find them here
You can browse other projects I've lying around on my harddisk here, or via
the web-interface to my cvs-repository.