Hi Sorin,

Yes, GDI+ supports Anti-Alias
Check for the GpImage class inside _gdiplus.vcx
Then have a look at "SmoothingMode"

Here are the constants relate to that.
You might be interested in 4 - Anti Alias

#DEFINE SmoothingModeInvalid  -1 
#DEFINE SmoothingModeDefault  0 
#DEFINE SmoothingModeHighSpeed  1 
#DEFINE SmoothingModeHighQuality 2 
#DEFINE SmoothingModeNone   3 
#DEFINE SmoothingModeAntiAlias  4 

Regards

Cesar