SearchToSale
A script that puts a search box on site, and allows redirect to specific URLs based on matches to the search term. [Commercial] http://searchtosale.com/
RuterSoft
A search engine software written in perl with spidering, administrative control and advanced syntax features. http://www.ruter.net/soft/
RiSearch
Simple, powerful and fast search engine. [For non-commercial] http://risearch.org/
SmartPPC
Offers PPC search engine and toolbar. Includes news, demo, forum and product description. http://www.smartppc.com/
Turbo Seek
Yahoo style directory and search engine with ease. [Adv shareware] http://www.focalmedia.net/index_tb.html
YellowMaker
A self-administered business directory designed to set up a professional yellow pages on the web. http://www.yellowmaker.com/cgi-bin/yellowmaker/scripts/index.pl
WebLinks Web Directory Generator
This software can build Yahoo style Web directory. WebLinks is an add-on feature of the BizDB Web database software. http://www.cnctek.com/weblinks/about_weblinks.html
ProLinkz
A CGI script that will let you easily track, redirect/disguise and manage all your site's internal and promotional links. [Commercial] http://www.prolinkz.com/
PowerSeek SQL
Search engine and directory portal application with customization features. Demo, support forum and installation instructions. http://www.focalmedia.net/pseek.html
Friendly Links
An user-friendly links exchange management and directory publication system in Perl that provides a complete links directory management mechanism for a website. By Friendly Infosys Corporation. [Commercial] http://www.friendlyinfosys.com/friendly_links.html
Directory Pro
CGI scripts written which allows creation of own Yahoo or Dmoz style directory. http://www.cosmicflame.com/scripts/dirpro.shtml
Cougasoft
Free CGI scripts - emphasis on link-management. [Collection] http://www.cougasoft.org/
HTML Site Index Generator
An multi-page HTML site index generator that easily handles virtual domains. http://marginalhacks.com/Hacks/site_index/
MonoPro Link System
Create portal-style link directory with multiple categories and subcategories. [Commercial, online demo] http://www.monopro.com/index.html?linksystem
The Computer Science Directory currently has categories, which include links along with indexed pages.