Searchify is an embedded website search and search marketing application that allows you complete control over search results. The Searchify dashboard lets you create the most relevant search results and custom results so that you can promote specific product results to your website users.
You can rank results based on relevance and sales performance along with suggested results based on keyword search and also smart searches - result suggestions based on the first letters of user searches.
Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
Site Search 360 - Site Search 360 enhances and improves your built-in CMS or product search with autocompletion, semantic search, filters, facets, detailed analytics, and a whole lot of customization options.
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
SeekStorm - SeekStorm - Search as a Service: Affordable, high performance search & crawling.
Google Custom Search - Google Custom Search enables you to create a search engine for your website, your blog, or a collection of websites.
ElasticHQ - Tool for ElasticSearch management and monitoring.