Copernic:Customizable free metasearch tool which queries many engines, removes duplicates, and validates the results.
1-Click Answers: This free reference tool from Answers.com can look up quick answers in a range of authoritative sources, while you're working with any application.
Ferret Soft Webferret: A suite of tools for searching the internet using multiple engines and resources at the same time.
FirstStop WebSearch: Customizable desktop software for Windows that searches multiple search engines and websites simultaneously. Freeware and trialware versions available.
Geowhere: [Win] Multifeatured freeware that queries multiple search engines at once.
JOC MP3 Finder: A free tool to search and download MP3 files from the Net.
MindRetrieve: Open-source, browser-based application that searches the user's history of viewed pages.
PractiSearch: Free dockable web search toolbar that can launch searches in myriad search engines from many categories. Includes automatic translation and can be extended with more search engines.
Qube: Desktop client which offers browserless Internet meta-search. It searches any text already on screen (or manually entered) and retrieves collated results.
Sekhol: Auto Web Browser: Gratis metasearch software that queries several web search engines, accesses found web pages, and crawls their links. Free download.
SimpleFind: A free program that allows you to search information on the internet using top search engines. [Windows 9x/2K/ME]
Telescope Search: Free metasearch tool, which queries several search engines in six categories, removes duplicates, and also supplies an option to check links.
termBlaster: This flexible software launches searches from any chosen search engine in its built-in browser; web, music, and game categories are preloaded. Users can quickly do a search from the desktop search bar.