Revamped core technologies make coding easier, more exciting for software developers. When it comes to Apple‘s new operating system, Leopard, users are likely to notice the flashy graphics and animations, the tight integration of applications and the speed with which it churns through data. What they don’t see are a large number of the under-the-hood changes that Apple built in so that its own developers — and those who come up with third-party apps — use all of that underlying software goodness.