Back in 1999, you would use this dialog editor to build custom dialogs for SOFTIMAGE|3D shaders and plugins:

The dialog editor would generate the .cus file that specified the layout of the custom dialog. For example, this simple dialog box:

was defined by this .cus file:

Dialog
1200, "Breakup", 12, 1, -1, 442, 385, 836, 638
1, 2, "Ok", 700, 459, 790, 496, 0
2, 2, "Cancel", 593, 459, 683, 496, 0
3, 0, "", 697, 459, 697, 459, 0
4, 0, "", 697, 459, 697, 459, 0
5, 0, "", 697, 459, 697, 459, 0
6, 0, "", 697, 459, 697, 459, 0
7, 0, "", 697, 459, 697, 459, 0
8, 0, "", 697, 459, 697, 459, 0
9, 0, "", 697, 459, 697, 459, 0
10, 0, "", 697, 459, 697, 459, 0
11, 0, "", 697, 459, 697, 459, 0
12, 3, "Tagged Points Only",590, 565, 772, 580, 0

_SYMBOLS
TAG 12
_END