Google - The most popular search engine on the web, thus the most important.
Submission: Free (actually the best way to be included in the index is to have Google find you from an external link)
AltaVista - First searchable, full-text database for the Internet. Now all main results are compiled by Yahoo!
Submission: through Yahoo!
All The Web- Search engine, originally owned by FAST but was sold to Overture. The main results are compiled by Yahoo!
Submission: through Yahoo!
AOL - Founded in 1985, AOL has grown to offer online services to more than 35 million around the world.
Submission: Feeds from Google and Dmoz
Ask - Launched in Berkeley, California in1995 as an attempt to 'humanize' the online search experience. Originally known as Ask Jeeves is now called just Ask. Now part of Interactive Search Holdings which includes iWon, Excite and Teoma.
Submission: Fee
DMOZ - Comprehensive directory compiled by volunteer editors.
Submission: Free
Excite - Meta search engine purchased by Infospace. Part part of Interactive Search Holdings 'collection'.
Submission: Fee
Inktomi - Owned by Yahoo!, it is the leading provider of paid inclusion services (PPC).
Submission: Fee
Iwon - Search engine powered by a variety of sources
Submission: Fee
Lycos / HotBot - Hotbot is owned and is a transparent arm of Lycos who is one of the oldest search engines.
Submission: Fee
MSN - Search engine powered by a variety of sources; However, a team of editors monitors the most popular searches and hand-pick sites that are most relevant.
Submission: Free
Overture - Acquired by Yahoo, a search engine that auctions its rankings.
Submission: Fee
Teoma - Acquired by Ask Jeeves, ranks a page based on Subject-Specific Popularity.
Submission: Fee
Yahoo! - Web index pioneer with a huge directory.
Submission: Fee
Notable
IXQuick - Highly rated meta search.