The following programs will create square terrain and are obtained from this thread:
http://www.battleforums.com/showthread.php?s=&threadid=15582
ScmDraft:Alpha
This program is basically an advance Staredit Program. It has features that Sc X-tra Editor doesn't have and doesn't have features that Sc X-tra Editor has. Most people use this program to Stack minerals and other stuff. Another usefull feature it has is that it can create 1x1(Square) Terrain.
ScmDraft:Beta
This program is almost like ScmDraft:Alpha but it's a little worse. It can still place Square terrain, but it won't show up on the map when you place Square terrain. To make it show up. Go to rectangle terrain and then just place 1 rectangle terrain anywhere. After you do that, it'll show up the square terrain that you have placed. You cannot place regular diamond terrain. If you do, a box will show up and show up numbers. If it does, just hold enter until the boxes don't appear anymore. This program can also let you put map revealers for a certain player all over the map in a few clicks.
Guedit 3.6 Alpha
This nifty program can do a lot of nice stuff that every map maker needs. It can protect maps, set upgrades to instant, save triggers as text, create square and tweaky terrain, change the map terrain, and change player's colors.(can have all players to be black)
And Isom.
I cannot add colors to a thread title. The admins don't want to enable html to the forums. So I'm busted.