From the “Microsoft Acquires Calista Technologies” post on the Terminal Services Team Blog…

Calista’s products dramatically improve the end-user experience of 3D and multimedia delivery for Microsoft multimedia applications, virtualized desktop deployments, and server-hosted virtualized desktops or applications using Windows Terminal Services. Their technologies support all file and streaming media type available, and optimize Microsoft’s widely available Remote Desktop Protocol (RDP) to reduce the network bandwidth requirements for remote display of rich media content; thus, remote workers can receive a modern Windows desktop experience without the need for dedicated hardware.