zengraph is an ancient project of mine dragged to ruby kicking and screaming from my perl days. It took structured data of any form, for example a mailbox full of test results each having a line like:
1197 tests, 6380 assertions, 0 failures, 0 errors, 41 skips
and generate a graph off the number of tests, assertions, failures, errors, and skips over time using gnuplot. Nothing special, but it was configurable enough to make daily graphs of test results, web server logs, etc… anything we needed.
I haven’t touched this code in 10 years, literally. It probably still works, but at the very least will look ugly as sin since gnuplot is pretty jaggy (have they improved this at all?).
I doubt I’ll ever bother to release this as a gem.
git clone git://github.com/seattlerb/zengraph