Rocket Folio Views

Folio Views is a data storage/retrieval system, that uses a custom (Folio) database to quickly search all of the content. A Folio infobase is a free-form database of text, graphics, and other data created using Rocket Folio Views or Folio Builder. Folio infobases serve as secure, fully indexed, content containers that make information more valuable to end-users—and more manageable for publishers and corporate information managers.

It has a hierarchical table of contents, with the ability to search specific branches, etc. It works as a simple editor, so all the RTF style formatting is supported. Many commercial products use it, when publishing large collections of text. Searching is its forte, where it can be narrowed down to specific strings, paragraphs, branches, etc.