iCloud and Dropbox alternatives #

Host your own:

ownCloud "gives you easy and universal access to all of your files. It also provides a platform to easily view, sync and share your contacts, calendars, bookmarks and files across all your devices ... Photo albums are automatically created for uploaded photos and make it easy to scroll through your pictures." Open source; supports WebDAV, CardDAV, and CalDAV.
iFolder - Open source Dropbox alternative. Linux, OS X, and Windows clients available.
SparkleShare - Open source Dropbox alternative. Linux, OS X, and Windows clients available.
Syncany "is an open-source cloud storage and filesharing application. It allows users to backup and share certain folders of their workstations using any kind of storage, e.g. FTP, Amazon S3 or Google Storage."

Hosted by someone else:

fruux - "Contacts. Calendars. Tasks. Always in sync." Free for up to 3 devices (no paid plans available yet); supports CardDAV and CalDAV.

Hybrid:

Pogoplug PC - Host your own cloud using your PC or Mac. One time $29.95 payment; though files are hosted locally, login is through Pogoplug service.
Tonido - Host your own cloud from your Linux, Mac, or Linux computer. Login is through Tonido service.

/misc | Apr 02, 2012