32-Bit version of MapWinGIS v4.9.

It should be backwards compatible with previous versions of MapWinGIS v4.9.

MapWinGIS v4.9 is not backwards compatible with MapWinGIS v4.8.*. All methods and properties are available, but some of them have small changes in their names to remove typos. With a little effort it should be possible to upgrade.
If you are a developer it is recommended to upgrade to this version. It has a lot of new features like a Raster Calculator and Reclassify Raster.
Look at this page (http://www.mapwindow.org/documentation/mapwingis4.9/newpage492.html) to see all changes.