WLoggerDaemon is a project mainly written in OBJECTIVE-C and C, it's free.
Mac OS X Daemon that logs weather data from Oregon Scientific WMR100N, RMS300A or WMRS200
WLoggerDaemon is a mac daemon (background application) that connects with USB to some weather stations from Oregon Scientifics. It currently works with WMR100, WMRS200, RMS300 and RMS600. WLoggerDaemon logs data to CouchDB and/or sends Twitter updates every hour.
NB! The current implementation saves passwords in a prefs file, so don't use your most valuable secrets. I will change this ASAP.