I think it’s probably the best self-hosted file sync tool on the market.

It’s a full web application platform, an indispensable tool for a business of any size that needs to deploy any kind of custom web UI.

If you build an ownCloud app, you’ve got authentication, storage, security, caching, and database layers already fully baked for you. You just need to build your UI and custom logic. Your app doesn’t even need to interact with files, sync, or interact with other ownCloud features.

Any web UI can be included without ownCloud. It can even be a portal to web interfaces of other applications within a business using the external app to display external sites within ownCloud. This is the case as long as that site allows itself to be displayed within a frame.