From CpapWiki
Sleepyhead
SleepyHead is a free, cross-platform, open-source research tool for exploring data produced by CPAP machines, and related equipment, which are used in the treatment of sleep apnea and other sleep disorders.
SleepyHead supports data capable CPAP machine models from the following series: ResMed S9, Philips Respirioncs System One, Fisher & Paykel ICON and Devilbiss Intellipap. As of 0.9.8, SleepyHead works with the full range of Contec CMS50 series of Oximeters (and clones, like Pulox) either standalone or synced with CPAP data.
SleepyHead also supports ResMed and PRS1 oximeter attachments, and file import from ChoiceMMed MD300W1 oximeters.
Download here.