The XbaeMatrix is a Motif-based widget which displays a grid of cells
in the same manner as a spreadsheet.  The cell array is scrollable,
editable, and otherwise reasonably configurable in appearance. Each
cell usually displays text, but pixmaps can also be displayed (not
editeable). The XbaeMatrix looks to some extent like a grid of
XmTextField widgets, but is actually implemented with a single
XmTextField. This means a big performance improvement due to less
overhead.

WWW: http://xbae.sourceforge.net/