One of Java's key strengths is its portability. The Java virtual machine (JVM) is a high-performance, portable, and successful substrate. However, the tectonic shift in Java ownership (from Sun to Oracle) has caused aftershocks, destabilizing Java APIs. This has been exacerbated by neglect and deprecation. Deprecation warnings aren't generally deemed serious, as programs continue to run. However, sometimes entire JVMs are deprecated. The biggest threat to Java is Apple's banning of Java on the iPhone and the deprecation of the new JVM on the Mac OS.