[plt-scheme] Grid or Table Widget

I remember various occasions when folks on this list asked about the
existence of a "grid" or "table" widget. Did anyone ever make one?

I have a Linux process browser:

        http://www.theworld.com/~proteus/system-processes.png

I'd like to show the pid, owner, and command for each entry. One thing
I tried was to put all three items in a nicely formatted string, and
put those into the list-box% object. However, the non-fixed-width font
means that the columns don't line up properly.

Anyone have any suggestions as to how I can achieve the desired
formatting using the existing MrEd widgets? I thought about using an
editor object with a fixed width font, and dumping the lines to that.

Ed