The best enterprise search products on the market come from Autonomy, Endeca, the Microsoft subsidiary Fast and Vivisimo, but Google's Search Appliance continues to dominate the market in terms of brand awareness and sheer number of customers, Forrester Research says in a new report.

IBM and Oracle offer competitive search tools but lack some mature features and don't have enough customer deployments "to test and optimize scalability in different scenarios of query complexity and document size," analyst Leslie Owens writes in a Forrester Wave report on the enterprise search market.

The vendor Coveo Solutions and another Microsoft product, the Search Server, are both strong performers but still lag behind the market leaders, Forrester says.

Enterprise search is becoming increasingly important, playing a role in e-commerce, online directory sites, and in internal networks, where digital content is growing because of Web 2.0 technologies like wikis and blogs. Search is also becoming vital to industries facing requirements to control and produce digital communications and records in a timely manner, Owens notes.

Customers can choose from about 30 vendors, 11 of which were profiled by Forrester, offering products that range in price from free to seven figures.

As a result of rivalry involving IBM, Microsoft and Google, "enterprise search became free in the fall of 2006 with the release of IBM OmniFind Yahoo! Edition, only to be matched by the release of Microsoft's Search Server Express 2008 in March of this year," Forrester says. "Expect prices to continue to go down for commodity search tools."

Users are still frustrated by the limitations of enterprise search, finds a June study by AIIM, a nonprofit content-management research firm. Nearly half (49%) of respondents to an AIIM poll of 500 businesses said it's difficult and time-consuming to find information necessary to do their jobs, and 69% said less than half of their enterprise's information is searchable.

Enterprises themselves must accept much of the blame, because they have largely failed to take a strategic approach to enterprise search, AIIM says.

Picking the right vendor is important, though, Forrester notes. Customers should research scalability and security requirements, determine what features really matter, and take vendor claims with a grain of salt. Vendors like to say their products let IT pros manipulate search algorithms to change relevance rankings. But this can be time-consuming and have unintended consequences.

"Unless you are willing to sign up for painstakingly biasing the relevance algorithm at a metadata attribute level, and then comprehensively testing the system for recall and precision, products that allow basic results boosting may be sufficient," Forrester writes.

Writing specifically about the vendors, Forrester credits Autonomy and Fast with being "longtime rivals and the forefathers of the enterprise search business. Each sells a rich tool kit that more than meets the needs of [information and knowledge management] pros deploying search across the enterprise."

Autonomy offers the most complete product reviewed by Forrester "with the best core technology architecture and security capabilities." But some customers believe Autonomy's service and support offerings are lacking compared with the cost and complexity of the product, says Forrester, which interviewed 22 user companies.