There isn't much information. The header and lib file are in the Xcode app at Contents/Developer/usr/include/AppleTextureConverter.h and Contents/Developer/usr/lib/libAppleTextureConverter.a. The header has some minimal examples in the comments, and a list of libraries and frameworks you'll need to link against.
The lib also needs to link with analytics_send_event_lazy, which seems to be in the private framework CoreAnalytics. This isn't listed in the required frameworks. I currently have this in an xcconfig file, but I'm not sure what the "correct" solution is.
MY_PRIVATE_FRAMEWORKS_DIR = $(DEVELOPER_SDK_DIR)/MacOSX.sdk/System/Library/PrivateFrameworks
OTHER_LDFLAGS = $(inherited) -F$(MY_PRIVATE_FRAMEWORKS_DIR) -framework CoreAnalytics
The windows version is available in the Metal Developer Tools for Windows.
That's as far as I've gotten, will try compressing some files next.