[4] Paul Flaherty came up with the original idea,[5][6] along with Louis Monier and Michael Burrows, who wrote the Web crawler and indexer, respectively.

[7][8] Ilene H. Lang was the founding CEO of AltaVista after being recruited by Digital Equipment Corporation to build its software business.

[9] At launch, the service had two innovations that put it ahead of other search engines available at the time: It used a fast, multi-threaded crawler (Scooter) that could cover many more Web pages than were believed to exist at the time, and it had an efficient back-end search, running on advanced hardware.

[11] Another distinguishing feature of AltaVista was its minimalistic interface, which was lost when it became a Web portal, but regained when it refocused its efforts on its search function.

[14] By using the data collected by the crawler, employees from AltaVista, together with others from IBM and Compaq, were the first to analyze the strength of connections within the budding World Wide Web in a seminal study in 2000.

A "session" is a series of queries by a single user made clustered within a small range of time.

It was a poor substitute for cookies, particularly for large ISPs such as AOL, where ~10,000 of users shared a single IP address.

Under CEO Rod Schrock, AltaVista abandoned its streamlined search page and focused on adding features such as shopping and free e-mail.

In June 1999, Compaq sold a majority stake in AltaVista to CMGI, an Internet investment company.

[20] Meanwhile, it became clear that AltaVista's Web portal strategy was unsuccessful, and the search service began losing market share, especially to Google.

After a series of layoffs and several management changes, AltaVista gradually shed its portal features and refocused on search.

employee leaked PowerPoint slides indicating that the search engine would shut down as part of a consolidation at Yahoo!.

[27][28] To fight against an increasing number of malicious internet bots, AltaVista implemented the first practical CAPTCHA schemes to protect against fraudulent account registrations.

[29][30][31] They implemented it specifically to prevent bots from adding URLs to their web search engine.