Being a proponent of open source software, I've always found it annoying that the device I use most of the time -- my mobile phone -- runs some closed source proprietary system.
Munin collects information and plots parameters of your choice automatically and with minimal configuration. But if you can't find a plugin that captures the data you want to graph, you might have to roll your own.
A distributed database based on the distributed Git version control system relies on a Perl script to help users track Internet orders. When the goods arrive, purchasers update their stock counts, wherever they may be at the time.
