Don't know what to call what I need.

I’m sure someone has the plugin I need but I don’t know how to search for it.
I’m looking for an interactive way for users to search for, view and download document files – mostly .pdf’s. These are exclusively public documents with no copy-write protection so I’m not concerned with limiting access.

I’v used google docs on sites but that’s too limited and not search-friendly, especially for what could be hundreds of documents adding up to thousands of pages, with new documents added weekly.

I know .pdf is not ideal for web search but I’m not creating these docs, only posting them for public access. I’m willing to learn if there are solutions to converting .pdf to something more web-friendly like html or whatever.

Specific plugin suggestions are appreciated but I’d also like to know what to call this class of plugins.

Thanks all.