Platform: Linux, BSD (compiled but not tested on AIX and Solaris). Price: free, open source, under GNU GPL
Features
Open Source, written in C++ using STL, some use of SQL database
for storage
Command line / config file search administration
Can index multiple sites at the same time using threads and asynchronous
DNS lookups
Option to show indexing progress (-N)
HTTP and proxy HTTP and FTP indexing
Search engine operates while index is updating.
Option for near-real-time index updating
Will index documents protected by SSL using HTTPS
Supports basic authentication (user name and password)
Indexes HTML and text documents
Requires external programs or scripts to index other file formats
Language support includes Unicode for mixing character sets in index, charset
guessing, and language mappings for Roman characters including Czech, Danish,
Dutch, English, French, German, Italian, Norwegian, Polish, Portuguese, Russian,
Slovak, Spanish, Turkish, Ukrainian and non-Roman: Arabic, Greek, Hebrew,
Japanese, Chinese (BIG5 and Gb2312) and Korean.
Duplicate detection
Very scalable, to several million documents
Zone searching (limit to a site or section of a site)
Standard and advanced search capabilities, including phrase search, Boolean
queries and wildcard searches.
Spellchecking with ispell
Optional stemming for search results.
Hit highlighting in search results
Weight given to inbound links (pointing at a page) in relevance ranking
Local caching of indexed pages
Easy to customize results pages
Can cluster search results by site
Some code based on mnoGoSearch, but they
have taken different paths
Examples
ASPSeek.com -
portal covering Application Service Providers