PCRaster 4.3.0 is the currently maintained version. You can find more information here.
PCRaster version 4.2
PCRaster version 4.1
Information about PCRaster 4.1.0 is available here.
PCRaster version 4.0
PCRaster version 3 (deprecated)
Version 3 of PCRaster for Linux and Windows operating systems has been completely replaced by version 4. We do not provide updates for version 3 any longer. We recommend to download the latest version of PCRaster.
In case you have compelling reasons for using PCRaster 3 please contact email@example.com.