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. SleepyHead works with Contec CMS50D+/E/F Oximeters either standalone or synced with CPAP data, up to firmware revision v3.7, plus data files produced by the SpO2Review software for newer firmware devices.