Catfish

Open source File searching tool

Catfish is a versatile file searching tool. Catfish is a search GUI powered by locate and find behind the scenes, with auto-completion from Zeitgeist and locate. The advanced options allow filtering by date and file type. The interface is intentionally lightweight and simple, using only GTK+.

Regain - Open Source Search Tool

Search the contents of your files not just the file names. Regain is a search engine similar to web search engines like Google, with the difference that you don't search the web, but your own files and documents. Using regain you can search through large portions of data (several gigabytes!) in split seconds! This is possible by using a search index. regain crawls through your files or webpages, extracts all text and puts it in a smart search index. All this happens in the background. So if you want to search something you get the results immediately.

Recoll - Open Source Search Tool

This package is a personal full text search package which is based on a very strong backend (Xapian), for which it provides an easy to use and feature-rich interface. Avaliable through repositories.

Beagle - Open Source Search Tool

Beagle is a search system for Linux and other such modern Unix-like systems, enabling the user to search documents, chat logs, email and contact lists in a similar way to Spotlight in Mac OS X, and Windows Search or Google Desktop (third party) under Linux or Microsoft Windows. It is not actively developed.