TWAIN and TWAIN Direct are application programming interfaces (APIs) and communication protocols that regulate communication between software and digital imaging devices, such as image scanners and digital cameras. TWAIN is supported on Microsoft Windows, Linux and Mac OS X. The three key elements of TWAIN are: Both the application and the device driver must support TWAIN for the interface to be successfully used. The first release was in 1992,and it was last updated in 2021.