Apple has revealed some of the 150 features of its new Tiger operating system, version 10.4, due for release during the first half of 2005.

New dynamic search facilities will be key to the success of the release, as will the extension of the audio and video features and support for new graphics standards.

Phil Schiller, senior vice president of worldwide product marketing at Apple, claimed that the latest features, including 64-bit support and 32-bit backwards capability, would be available more than a year before Microsoft's Longhorn.

"I'm not sure anyone knows when Longhorn is coming, but Tiger will be ready before it," he said.

Tiger introduces Spotlight, a search facility that can locate files on a hard drive using content and metadata, as well as by filename.

Schiller explained that as hard drives hold hundreds of thousands of files, a new search engine that could search standard document formats in the way iTunes does with its libraries would increase the PC's usability.

Another key component of Tiger will be the ability to host up to 10 people on an audio link using iChat AV, or up to four people via a video link.

The operating system also contains support for the Really Simple Syndication feeds already embedded in some of the most popular websites, allowing users to track updates.

And extended standards support continues for rich media content with the introduction of the latest MPEG standard, H.264.

This will allow users to view and manipulate high-definition content using Tiger at up to four times the resolution of current systems.

It will also allow users to switch between active windows, and features a series of mini-tools such as currency converters and a world clock, thus saving users from minimising windows to find a tool.

An 'Automator' function brings basic workflow capabilities to applications, allowing users to automate repetitive tasks like importing multiple pictures from iPhotos into a DVD slideshow.