Download
elibsrv is a light, standalone OPDS server for Linux. It allows to generate an OPDS repository of EPUB and/or PDF files scanned from on-disk directories. It also provides a simple html interface for non-OPDS humans, which makes it a good fit for both OPDS-aware devices (like Android with FBReader or Aldiko) and browsers with EPUB/PDF capabilities (for ex. Firefox with the excellent EPUBReader plugin).
It's worth noting that elibsrv is a complete solution - ie. it doesn't rely on third party software (most similar solutions are designed to work with Calibre...). Requires only PHP with sqlite.
If you'd like to see how it looks for real, feel free to test on my 'demo' server (contains a few public domain books) - you can test it both using a web browser and an OPDS device:
http://elibsrv-demo.viste.fr
Project Samples
