Infrex
Rulebase engine, allows separating business rules from program code, so rules can be changed fast without having to change programs. Has rule editor, rule translator (emits C/C++/C#/Java code from rulebase), rule interpreter (interprets rules in rulebase file at run-time). [Commercial]
http://www.tcs.com/0_products/infrex/

PiVoT Software Services Limited
The Social Media blog is your single destination for updates on the AIM Buddy blog, the AIM Pages blog, the AOL Community Info blog, the Expressions Factory, the Marvelous Mob and the Social Media Mess blog.
http://members.aol.com/pivotsoftware/

InRule .NET Rule Engine
InRule Technology provides pure .NET Business Rule Engine software for faster implementation of rules-based applications and more rapid development of Windows Workflow Foundation and BizTalk systems.
http://www.inrule.com

BlueRobot.com
Two and three column layouts, tutorials on auto-width and negative width margins, and a fix for the @import rule and how Internet Explorer phrases the rule.
http://www.bluerobot.com/

Rule Learning
Code estimates the population rule learning model on experimental data.
http://www.eco.utexas.edu/Homepages/Graduate/Haruvy/experimental/rlindx.htm

Make Your Own Circular Slide Rule
Templates, directions, and some links to other slide rule sites.
http://solar.physics.montana.edu/kankel/math/csr.html

Apple Steel Rule Die Company
Produces wide range of steel rule dies and provides die and laser cutting as well as general tool and die services. Examples of end-products and their applications.
http://www.appledie.com

Adams Technologies Inc.
Adams Technologies - Home of the EasyBender! Supplying automated benders, waterjets, dieboard lasers, routers, samplemaking plotters, and CAD software to the steel rule diemaking and diecutting industry
http://www.adamstechnologies.com/

History of the Slide Rule
Basic facts involving the development of the slide rule. Includes diagrams and links to information on various types of slide rules.
http://www.hpmuseum.org/sliderul.htm

Eric's Introduction to the Slide Rule
Slide rule resources and links
http://www.sliderule.ca/intro.htm