>I don't know about uptime, but most of the new programming languages have no undefined behavior (a Java program always behaves as a Java program whatever your bugs are), while most of the old languages do have undefined behavior (even Ada has garbage-initialized variables.)

BTW, Java does have implementation-defined or unspecified behavior (for instance, using the same objects from different threads without proper coordination), but there's much less of it and it's easier to avoid.