ActiveKB
- A web based knowledge base application that allows users to manage their knowledge base or frequently asked questions. [Commercial]
- http://www.interspire.com/activekb/

SocketKB
- A flexible knowledge base management system based on PHP and MySQL. [Commercial]
- http://www.socketkb.com

Idevspot iSupport
- A hybrid customer support script with a fully customizable template system, including support tickets, knowledge base, FAQ, customer testimonials.
- http://www.idevspot.com/index.php?page=p_detail~1

WSN Knowledge Base
- Customizable PHP/MySQL knowledge base script. [Commercial]
- http://scripts.webmastersite.net/wsnkb/

Faq Manager Pro
- A FAQ and knowledgebase solution with easy installation. Full layout and design control. Multi-Language support. [Commercial]
- http://www.faq-manager-pro.com

Softbiz FAQ Script
- Configurable, multidimentional FAQ script to run web sites FAQ Section. [Commercial]
- http://www.softbizscripts.com/FAQ-script-features.php

Lore
- An advanced knowledge base management system based on PHP, MySQL, and Smarty. [Commercial]
- http://www.pineappletechnologies.com/products/lore/

Knowledge Builder
- A knowledge base / FAQ solution for commercial and personal use.
- http://www.activecampaign.com/kb/

piFAQ
- A simple script that will help to create (and manage) FAQ page on site. It is based on PHP, MySQL and FastTemplate so it's fast and easy in configuration.
- http://pifaq.sourceforge.net/

Frequently Asked Questions Engine
- An open source PHP system which lets you make your FAQ dynamic in nature, easier to maintain, and searchable.
- http://www.codegrunt.com/