High Quality Content by WIKIPEDIA articles! CrashPlan is backup software that allows Windows, Mac, Linux and Solaris users to back up their data to an offsite data center, computers belonging to friends and family, as well as to attached drives / shared folders. There is a free version (for non-datacenter backups) and CrashPlan+ which is for backing up to CrashPlan`s servers. Both versions allow users to back up data automatically. Files are encrypted using 448-bit Blowfish (128-bit with the free version) encryption for CrashPlan+ before transmission.