- Alkaline (Vestris)
- Amberfish
- ASPSeek
- AurWeb
- Autonomy Search Server
- Arexera (formerly TEC-IMS)
- Convera RetrievalWare
- Datapark Search
- DeepSearch
- Doclinx TeraXML
- EasyAsk
- Endeca Commerce, Catalog and Enterprise
Search
- Excalibur RetrievalWare
- Extense
- FAST Search Server
- Google Search Appliance
- Glimpse
- HomePageSearchEngine
- ht://Dig
- Htgrep (Perl)
- Hummingbird Search Server (formerly
Fulcrum Search Server)
- IntuiFind (Mercado)
- InQuira for Search
- Intelligenx (formerly i411) Discovery Engine
- Inxight SmartDiscovery
- K2 (Verity)
- LexiQuest LexiGuide language processor
- Lotus Extended Search (Domino)
- Mercado IntuiFind
- mnoGoSearch (formerly UdmSearch)
- Namazu
- Nav4
- Netrics Search (previously LikeIt)
- OmniFind from IBM and Yahoo OpenFTS
- OpenText - LiveLink
- OpenWebSpider (OWS)
- Oracle Matchpoint (formerly Triplehop)
- Oracle Text, Ultra Search and interMedia
- Panoptic Search
- Perl Scripts
- PLWeb from PLS
- QueryServer Metasearch Engine
- SearchExpress
- Siderean Seamark Faceted Metadata Search
- S.L.I. Search
- SmartDiscovery (Inxight)
- Solr
- Sphinx
Subject Search Server (SSServer)
- SWISH-E
- SWISH++
- Thunderstone Webinator
- TYPENGO N300 Search
- Ultraseek (Autonomy)
- Verity - Search97 & K2 (now Autonomy)
- Vivisimo Search, Clustering and MetaSearch Engines
- WebCat
- WebGlimpse
- Zebra
