The Slate is, we feel, a powerful and useful tool that provides a significant increase in abstraction over the Tk canvas. Because it is written entirely in Tcl/[incr Tcl], it is highly portable and should work with any other canvas extension.
The Slate is part of the Tycho user interface system [5], which can be obtained from the Tycho home page:
https://ptolemy.eecs.berkeley.edu/tycho
Current development versions of the Slate can be obtained from:
https://ptolemy.eecs.berkeley.edu/~johnr/code/slate