ownCloud is a software system that provides file hosting service in a general sense. Commonly used, Dropbox is free and open source software, unlike Google Drive
Users can install ownCloud into a dedicated server and use it at no cost and without any limit on the amount of storage or the number of connected clients (except for the hard drive).
Desktop clients are provided with desktop clients for Windows, OS X, or Linux computers to synchronize their ownCloud servers and files.
There are also mobile clients for iOS and Android devices. Files and other data (such as calendars, contacts, and bookmarks) can be accessed using a web browser without any additional writing required