For dynamically loaded plugins (or extension modules or whatever you want to call that feature). And because of some weird misfeatures of windows dynamic linker

For dynamically loaded plugins (or extension modules or whatever you want to call that feature). And because of some weird misfeatures of windows dynamic linker you pretty much have to break your application into pile of discrete DLLs if you want to dynamically load anything useful (or pass pointers to huge structs of pointers around, as is done by JVM's JNI).