All the products tested are intuitive, but IBM's OmniFind Yahoo edition absolutely buries rivals in terms of usability. A solid basic search product, the only major features it lacks are connectivity to more-advanced content systems and granular security options, though the product does provide an API that can be used to add more security features. And, the price is right (it's free).
ISYS is a solid performer, with a particularly interesting feature that lets users add more weight to a keyword, and thus more relevance to a document, when it's found in a specific meta field within a document. A user could tell the query engine to give higher relevance to documents that were authored by our friend Joe Sixpack, for example.
With today's search technologies, tuning is inevitable. Mondosoft provides a feature called Behavior Tracking that helps you find out what employees are searching for, and how successful their searches are. Although it's lacking in security, the system can generate summary reports.
Keeping content in the search index up-to-date is crucial. Thunderstone provides Adaptive Indexing to help keep indexes in tune; it works by automatically recognizing content that changes frequently and revisiting those documents regularly. Adaptive Indexing also reduces bandwidth use because it doesn't rescan every document on the same set schedule.
Although Vivisimo's interface is confusing, it does provide extensive and extensible parsing capabilities for use with structured content. The crawler can be told to ignore things like headers and footers on HTML pages, for example, or users could supply specific tags that should be ignored when the page is indexed.
