I made my own book hosting website because I was tired of having my books scattered on different platforms, using different readers, and having problems syncing between devices.
My solution can run on any device that has a browser with HTML5 support. Everything is synchronized, so I can start reading on my pc, then jump to my tablet and continue from the same page. I can also find metadata and covers for my books automatically.
My website supports PDF and ePub files. Viewing PDF works great, but the ePub viewer is built on an open source library still under development so it can be a little unstable.