ownCloud
Free Personal
ownCloud is a free and opensource file sync and share app which is self hosted.
iCloud
Freemium
iCloud is a cloud storage and cloud computing service.
fruux
Freemium
fruux is a cross-platform synchronization service.
OwnDrive
Freemium
OwnDrive is easy to use free online storage service for businesses, professionals, and individuals to store, backup, collaborate and share files with others.
Kontact
Open Source
Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email.
Funambol
Open Source
Funambol is a provider of platforms that power many cloud services.
