Google added a new ART runtime with Android 4.4. How can I target my apk to both ART runtime and Dalvik runtime?
The dalvik or ART is only the runtime in the Android. As an app developer, you don't have to care about these differences. All you have to care about is your app's API level which is describing the dependence of the Android OS version.
And in Android 4.4, ART is only a development which is NOT the default runtime even if the release note describing that ART will make app use less memory and run quickly. If you want to find the different, you can wait for the next version of Android. In the opensource, I found the ART has been setting the default runtime selection.