Tweak is a graphical user interface (GUI) layer to the Squeak development environment, which in turn is an integrated development environment based on the Smalltalk-80 computer programming language. Tweak is an alternative to an earlier graphic user interface layer called Morphic. Development began in 2001.[1]
Applications that use the Tweak software include Sophie (version 1), a multimedia and e-book authoring system, and a family of virtual world systems: Open Cobalt, Teleplace and the Croquet Project. An experimental version of Etoys used Tweak instead of Morphic.[2]