UMSA helps you to connet your PC to a normal CRT via SCART. Imagine you want to install a MAME machine with reel arcade look and feel and decide to install a normal CRT with SCART interface. Then this is your solution. Install soft15Khz or something similar on your PC and use UMSA to connect the PC VGA interface to the SCART interface.
Simply, this is VGA 15Khz to SCART converter.