The basic features of the widgets are:

* multi-line cells

* support for embedded windows (one per cell)

* row & column spanning

* variable width/height columns/rows (interactively re-sizable)

* row and column titles

* multiple data sources ((Tcl array || Tcl command) &| internal
caching)

* supports standard Tk reliefs, fonts, colors, etc.

* x/y scrollbar support

* 'tag' styles per row, column or cell to change visual appearance

* in-cell editing - returns value back to data source

* support for disabled (read-only) tables or cells (via tags)

* multiple selection modes, with "active" cell

* multiple drawing modes to get optimal performance for larger
tables

* optional 'flashes' when things update

* cell validation support

* works everywhere Tk does (including Windows and Mac!)

* unicode support (Tk8.1+)