Virtual reality design firm specializing in custom design and development for medical training games and simulations.

3DLES offers project management, educational support, building and scripting for educational projects in OpenSim.

KatiJack Studio is a virtual design firm specializing in landscaping and building which offers region terrains on its website.

Virtual world development company working in Second Life and OpenSim.

Jon Brouchoud designs virtual environments, 3D experiences and serious game applications in Unity3D, Second Life and OpenSim.

ARCH Virtual provides resources and design services to clients using Second Life, OpenSim and Unity3D.

Daden offers consulting, design and building services in virtual worlds, with particular expertise in the areas of web and real world integration, and creating interactive virtual personalities.

Creative Twists Designs offers design, building and other services for companies considering Second Life and OpenSim deployments.