MapWindow is available from http://www.mapwindow.com and MWSWAT is available from the WaterBase website http://www.waterbase.org.
The WaterBase website also includes
- a tutorial document on running MWSWAT
- global landuse and soil data provided by Karim Abbaspour of Eawag
- global precipitation and temperature data
- global river basins maps
- a tutorial on preparing MWSWAT input maps from global ones
- data for two example watersheds for you try MWSWAT on
The WaterBase project has broader aims than providing MWSWAT. It hopes to develop an international network of users and developers of tools for Integrated Water Resource Management, particularly, but not exclusively, in developing countries. If you want to be involved, or kept informed about its activities, or have feedback on MWSWAT, then email waterbase.contact@waterbase.org.