Apple has seeded developers with new builds of the latest updates to Leopard (OS X 10.5.5), including the Server version of the OS, and Safari (version 4.0). While the Safari 4.0 Developer Preview includes enhanced support for HTML 5 features, the latest build of the next maintenance update to Leopard has one known issue.

Mac OS X 10.5.5

Courtesy of AppleInsider, we can inform you that the latest Mac OS X 10.5.5 seed, hitting mere days after the release of 9F17, has one known issue, particularly one related to general searching of email messages in Mail.

As far as Mac OS X 10.5.5 Leopard Server is concerned, build 9F22 includes five fixes, bringing their total number to almost four dozen, according to the news source. Build 9F22 asks developers to concentrate on seven core areas, including Chat Server, WebObjects, Wiki Server, and Server Admin, the publication reveals.

Safari 4

Alongside the release of new beta builds for OS X 10.5.5, Apple has also issued a new preview version of the upcoming Safari 4. Three separate developer previews were released (Leopard, Tiger and Windows versions). Reportedly, Safari 4 will have the ability to save webpages as "Web Applications". This new feature allows Safari to save pages like Fluid, a Leopard app that creates Site Specific Browsers. At the time Apple seeded developers with the first preview version of Safari 4, users were said to have the ability to choose how new windows will open. It is known for a fact now that Safari 4.0 incorporates many of the latest enhancements found in WebKit. According to MacRumors, quoting the same sources, the latest HTML 5 features supported include:

- CSS support for masks, gradients, reflections, and specifying a named canvas.
- Rudimentary support for the WAI-ARIA (Rich Internet Application) and cross-site XMLHttpRequest specifications.
- the ability to send messages between documents
- storage of data either locally or just for the user's session
- the option of running web applications outside of a browser or when disconnected from the network
- canvas pixel manipulation.

It has also been revealed that Safari 4 incorporates the latest SquirrelFish technology. SquirrelFish promises 1.6 times faster JavaScript performance as compared to Webkit / Safari 3.1. SquirrelFish is a register-based, direct-threaded, high-level bytecode engine, with a sliding register window calling convention. It slowly generates bytecodes from a syntax tree, using a simple one-pass compiler with built-in copy propagation.

Be sure to check back in soon for the OS X 10.5.5 Build 9F23 seed notes.