Steps I used to install graphite (http://graphite.wikidot.com) on OS X Lion Jan 14 2013.
Your Application sends stats over UDP to... statsd (the data collection agent) which sends the stats to... Carbon (the storage application) which stores the data in... Whisper db which is immediately cached and optimized for time-series data.
The Graphite webapp reads data from the Whisper db and the cache and show us pretty graphs.