As of January, 2012, this site is no longer being updated, due to work and health issues
Mailing List Archive
Price: Free, open source under the GNU General Public License.
Platform: Solaris, HP/UX, IRIX, SunOS, Linux, Mac OS X, Mac OS 9 (from Tenon.)
Potential Security Flaw: 3.1.0b2 through 3.1.5 and 3.2.0b3 users should upgrade.
Comparison of Free Search Engines : April 2006by Yiling Chen
Concentrates on indexing, query processing, retrieval and relevance. Covers Alkaline, Fluid Dynamics, ht://Dig, Juggernautsearch, mnoGoSearch, Perlfect, SWISH-E, Webinator, and Webglimpse. All of these search engines are are free, mainly on Unix, and many are open source software.
The Open Road: Using ht://Dig : April 2002by Joe "Zonker" Brockmeier
Part 1 is a short but helpful discussion of how the indexing and search work, formatting results, scheduling and configuration. Part 2 talks about tuning the search engine for speed and efficiency.
Comparing Open Source Indexers : May 29, 2001by Eric Lease Morgan
Describes the history and features of eight open-source search engines, freeWAIS-sf (aging code and hard to install, but good for searching email and public domain etexts); Harvest (powerful gathering features for frequently-changing data stores, good with structured documents); ht://Dig (tricky to configure, no phrase searching, automatic stemming and match word highlighting); Isearch (weak documentation and support, easy to install, dated interface, Z39.50 support); MPS Information Server (zippy indexing of both text and structured data, Z39.50 support, Perl API, limited documentation); SWISH-E (simple to install engine, CGIs in Perl and PHP still beta, good for HTML pages, recognizes new META tags, sorts results by field; WebGlimpse (easy to install and configure, requires commercial version for customized output); Yaz/Zebra (mainly Z39.50, no Perl API, mainly a toolkit to index and respond to distributed client queries). Article also points out that chaotic information is less than helpful and encourages organization, structure and vocabulary control.
I love it when a plan comes together : March 2001by David Gewirtz
Rambling but cheerful description of setting up a search engine for ZATZ web sites using ht://Dig, indexing only the appropriate articles and not the alternate forms or contents pages. Some digressions into robots.txt, Linux and PHP.
Search Engines: The Hunt Is On : October 16, 2000by Avi Rappoport
In-depth discussion of search engines for e-commerce and other web sites covers features and future trends, software vs. services, database vs. text searching, natural-language searching, and open-source search engines covering ht://Dig and mnoGoSearch.