I have taken over as maintainer of the perl Geo::METAR module for parsing METAR (Aviation routine weather report) data. Although METAR is supposed to be a strict format I find lots and lots of regional variations, newer versions, things that should not be used anymore and other things making parsing hard. I'm now using the 24-hour metar files from the National Weather Service Internet Weather Source and I use those to stresstest the METAR-parser, looking up things that make it fail completely and fixing those.