Offering usability and design consultancy to the e-commerce and client server markets in Europe. Located in London, United Kingdom.

Independent usability and user-centred design consultancy, based in Stockholm, Sweden.

Provider of usability testing and research for websites, consumer electronics, software and hardware products. Located in Texas, USA.

Design of custom usability testing environments, including stationary labs and portable labs. Located Georgia, USA.

Offers a range of services with a focus on user interfaces for web and non-web applications. Services available throughout the Asia Pacific. Located in Australia.

The portfolio and resume of Kyle Pero, a usability analyst, interaction designer, and information architect consultant based in Pennsylvania, USA.

Boston Web firm offering information architecture, interaction design, usability consulting, and copywriting.

Provider of user experience services utilizing usability testing, focus groups, market research, training and documentation. Located in California, Georgia, and Illinois, USA.

Specializes in usability engineering, graphic design and software engineering, Located in Germany (Ludwigsburg, Dortmund, Mannheim, Munich).

Provides usability consulting, research, training and conferences. Located in Massachusetts, United States.