With this service you can share material, documents, images or videos with other users securely. OwnCloud can also be used to create free applications on the cloud or to have a backup of your documents. OwnCloud can be installed on any server, and it's compatible with several servers.
OwnCloud allows you to access from any device, and can create automatic backups. Furthermore, all the data is encrypted, and it allows you to increase the file storage capacity. OwnCloud has support for plug-ins, user management, and code cleaning.
If you want to maintain the privacy of your data and files when you place them on the cloud, OwnCloud is a very good option.