(Independent Computing Architecture) An input/output presentation protocol from Citrix that governs the keyboard, mouse and screen formatting between clients and servers in a thin client environment. Originally known as the "Intelligent Console Architecture," ICA is used in Citrix's thin client products (see Citrix XenApp and Citrix XenDesktop).

The First Windows Thin Client Computing
Using Citrix's WinFrame on Windows NT in the mid-1990s, ICA was the first protocol to provide thin client computing for Windows. Soon after, Microsoft came out with its Terminal Services, based largely on Citrix software, but using the RDP protocol. Initially one of ICA's advantages, there is numerous ICA client support, including Windows, DOS, Mac, Unix, Linux and Java. See thin client, WinFrame and Terminal Services.