A simple X11 util program that let you select box easily.
- - - - - +---------------+
| WY-1 | |
| | WIN 1 |
| | |
| - - - - + - - -+--------+-------+
| | WY-2 | | | |
- + - - - +------+--------+ |
| | WIN 2 |
- - - - + - - -+--------+-------+
| | | |
WX-2
| |--------+-------|
WX-1
|---------------|