ZyIndex is not quite a search engine -- it's a research tool for complete recall, appropriate in situations where any missing data could be catastrophic. It's part of Zylabs Content, Records, and Knowledge Management systems, specializing in compliance, Legal Firms, Intelligence and Law Enforcement, Financial back office and related fields.
Blossom search is a hosted (remote) search service, which indexes one or more web servers using a spider, and stores the results on it's own servers. When a user types a query, the form goes to the Blossom service, which does the matching and relevance ranking, and returns the results with links to the original pages on the original servers. It has modern search features such as stemming, spelling suggestions, match terms highlighted in context, and proximity-based relevance. It's now the featured search on the SearchTools.com home page.