-Q8F- What does it take to get Tcl to compile under SCO Unix?

From: -VIII- Questions on building Tcl and friends on your system

A8F. Add a "#undef select" to tkEvent.c, and remove the reference to 
TK_EXCEPTION around line 460 of main.c.

Tk uses its own scheme for allocating the border colors for its 3D
widgets, which causes problems when running TK on a system with
"PseudoColor" display class, and a 16-cell colormap.

If you can't go to eight bitplanes, you can instead start the server
with a "-static" (Xsco) or "-analog" (Xsight) option, making the
display class become "StaticColor".  This makes the entire colormap
read-only, and it will return the color that most closely maps to the
desired color as possible.

This information is from Keith Amann <Keith_Amann@stortek.com>