The list of platforms below all support Mann Whitney to varying degrees.
It should be noted that Develve, Salstat and SOFA are free.
Develve – free software that runs on Windows and Linux. Mostly used in science and R&D.
Salstat – a free platform (provided you know how to install it) or pay a small fee and get an install package for Windows, Mac or Linux.
SAS – a large, expensive suite of products supporting every form of analysis known to man.
SOFA – a free statistics platform, well known for its ease of use. Runs on Linux, Mac and Windows.
StatTools – moderately priced Excel add on.
SPSS – IBM’s statistical platform which is widely used, but commercial licences are expensive.
WinSTAT – very inexpensive, but highly functional statistics Excel add on.