Pydio

See the following -

The Future of File Sharing: Integrating Pydio and ownCloud

The open source file sharing ecosystem accommodates a large variety of projects, each supplying their own solution, and each with a different approach. There are a lot of reasons to choose an open source solution rather than commercial solutions like Dropbox, Google Drive, iCloud, or OneDrive. These solutions offer to take away worries about managing your data but come with certain limitations, including a lack of control and integration into existing infrastructure. There are quite a few file sharing and sync alternatives available to users, including ownCloud and Pydio...

The Next Big Challenge for Open Source: Rich Collaboration Software

The file sync and share movement started over a decade ago, led by the likes of Dropbox, Google Drive, and others, and became popular very fast. The killer feature was having all your files available on all your devices. No more forgetting to bring that important document to a meeting, emailing files, or handling multiple USB sticks. Files were always there when you needed them! That its growth happened with the start of the smartphone age made file sync and share even more useful. But its popularity wasn't just about having access to your own files on all your devices: it also made sharing easier, enabling a new level of working together. No longer emailing documents, no longer being unsure whether your colleague's feedback came on the latest version of your draft, no longer fixing errors that were already fixed...