User Interface Toolkit (UIT) was a C++-language, object-oriented layer on top of the XView graphical toolkit. It was originally developed by the Sun Microsystems employees, Mark Soloway (left Sun in 1993) and Joe Warzecha (still an employee of Sun), as an internal tools project for Sun's Computer Integrated Manufacturing organization in 1990. In 1991, Mark Soloway got permission from Sun to contribute the UIT to the MIT X11 distribution. Mark Soloway continued development on the UIT, subsequently creating and releasing UITV2 in 1992. The source code is freely available.
