SeekStorm is a Search as a Service: web-scale, real-time, full text, instant search for your data and documents. SeekStorm is a Crawler as a Service: high-performance, focused crawler turns any website into JSON docs with structured data.
20x speed and 200x payload compared to Lucene 30x more queries & docs per $ spent than other SaaS
Azure Cognitive Search - Azure Search makes it easy to add powerful and sophisticated search capabilities to your website or...
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.
Google Cloud Search - Search across all your company's content in G Suite.
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
Amazon CloudSearch - Amazon CloudSearch is a fully-managed service in the cloud that makes it easy to set up, manage, and scale a search solution for your website.
Carrot2 - Carrot2 organizes your search results into topics. With an instant overview of what's available, you will quickly find what you're looking for.