SQR Tree is shareware ($25 to register). As stated in the SQR Users Group:
Please note that SQR Tree is a 32-bit program; you'll need Windows 95, 98, or NT to run
it. You'll also need a program to uncompress the ZIP archive (PKUNZIP, WinUnZip, etc.).
There are plenty of options included with the latest release of SQR Tree that control
the visual and printed representation of the SQR procedure calls.
To download the program go to the SQR Users Group Library Section (http://www.sqrug.com/ftp/sqrtree/). To
register select Register from the Help menu. For further enquiries contact Wayne Ivory.
wivory@kagi.com