ApTest
Innovative software testing solutions - tools and services for automated and manual testing of application software, Web sites, middleware, and system software.
http://www.aptest.com/

Software Research, Inc.
The eValid Website Testing and Analysis Suite helps organizations maintain e-Business presence, improve website quality and integrity, reduce down time, control costs, and enhance quality and delivered performance to increase customer satisfaction and profits. The eValid Suite supports browser-based client-side functional testing and validation, page timing and tuning, transaction monitoring, web site spidering and analysis, and realistic server loading. eValid is comprehensive, easy to use, scalable, cost-effective, and applies to any web browser enabled applications.
http://www.soft.com/

NSTL, Inc.
Large independent information technology testing organization. Provides hardware, software, e-commerce, internet and custom testing, government services, Multimedia Testing and Telecommunications Testing.
http://www.nstl.com/

Software Testing Sucks
Learn Software Testing. Learn how to make it fun
http://www.softwaretestingsucks.com/

Rice Consulting Services, Inc.
Specialists in software testing consulting, independent testing of e-commerce sites, training in testing processes and software process improvement. [OK]
http://www.riceconsulting.com/

STAQS - Software Testing and Quality Services
Resources and information for software testers, programmers, software engineers, and students interested in testing.
http://www.staqs.com/

RTTS
A professional services organization that specializes in the testing of IT applications and architecture. It is partners with Rational Software and Mercury Interactive and teach a variety of courses on both vendors' automated testing tools and in automated software testing methodology.
http://www.rttsweb.com/training/

TelSoft, Inc.
Dependable, reliable software testing and web site testing services
http://www.telsoft-inc.com/

Software QA Test Resource Center
Extensive SOFTWARE QA and TESTING information - large FAQ, lists of resources, and listing of 390 web site testing/management tools.
http://www.softwareqatest.com/

Red-Gate Software: .NET testing tools
.NET tools for developers, including a code and memory profiler and a tool for detecting unhandled exceptions in your code.
http://www.red-gate.com/products/dotnet_tools_overview.htm