Apple has released to developers a preview of Safari 5.1, which is expected to accompany the release of Lion and offers media caching for audio and video data, new "sandboxing" for the rendering process and for plug-ins, the expected full-screen mode and support for better keyboard control, AppleInsider reports. It also adds a new architecture for extensions, making them more powerful and customizable, and enhances support for CSS3 and other web formats.
