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 Download Page:
RobySue's Beginner's Guide to SleepyHead
Machine Choices Wiki by Archangle: [Machine Choices]
Supported Hardware machines [Supported Hardware]