QSWAT and MWSWAT is very similar in terms of interface design although they are programmed with different programming languages and in different GIS platform. In this video, these two SWAT tools are compared side-by-side to demonstrate the similarity. The guess is they are from the same development team. MWSWAT is developed first and QSWAT follows the design.
QSWAT is a plugin for QGIS and programmed with Python. The development starts from 2 years ago and gradually get popular. The latest release is QSWAT 1.5.
Today is Chinese New Year. Hope everyone very good luck in the year of dog!