Recoll

Recoll is a desktop full-text search tool. It finds keywords inside
documents as well as file names.

• Versions are available for Linux and MS Windows.
• A WEB front-end with preview and download features can replace or
  supplement the GUI for remote use.
• It can search most document formats. You may need external applications
  for text extraction.
• It can reach any storage place: files, archive members, email
  attachments, transparently handling decompression.
• One click will open the document inside a native editor or display an
  even quicker text preview.
• The software is free, open source, and licensed under the GPL.

For more detail, see the features page on the web site or the online documentation.

Most distributions feature prebuilt packages for Recoll, but if you need them, the instructions for building and
installing are here.