yuhong writes "After about a decade of development, CSS 2.1 has become a W3C recommendation. From the announcement: 'The current interoperability makes it easier than ever for developers and designers to enrich the toolkit. W3C expects future additions to CSS to be organized as independent modules, allowing smaller, more focused feature sets to progress and stabilize at their own pace. Some of these new features are already supported in browsers and other software in draft form (using the built-in CSS prefix mechanism designed for experimentation). As interoperability improves for each one, developers can transition to the standard to simplify their code. The CSS Working Group also publishes snapshots of which CSS features are supported interoperably in browsers; see, for instance, the most recent CSS Snapshot.'"