mike+ is developed by the Danish Hydrualic Institute (DHI) and is the transition of the older MIKE URBAN software to a new interface and database. MIKE+ is the brand of urban, river and flooding modelling and for water supply the MIKE+ Water Distribution software is used. While MIKE URBAN featured an Access database, MIKE+ features a SQLite database and faster loadtimes of the objects in the GUI.
MIKE+ is not featuring its own hydraulic engine, but relies on the epanet engine developed by the United States Environmental Protection Agency (EPA).
I use MIKE+ primarily for swedish and norwegian clients.