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.

Most distributions feature prebuilt packages for Recoll. In any case, here
are the instructions for building and
installing.