Apple has unveiled more details of its forthcoming OS X 10.5 Leopard operating system on a newly launched Leopard Technology Overview website for developers. 

The next version of the operating system is slated for release in the spring of 2007.

Many of the features outlined in the update involve opening up access to Apple's iLife programs to outside applications.

The iChat instant messaging and iCal calendaring applications will both be open to developers to use in their own applications.

Using Leopard, developers will be able to access iChat's video chat software to allow video conferencing in their own programs. QuickTime will also be updated, according to the bulletin, to allow applications to use video capture.

ICal will also be open to developers, allowing them to use the Calendar Store framework to access all iCal data. Apple claimed that this will allow applications to use data from iCal and Mail for such things as schedules and to-do lists.

The bulletin also stated that Apple's OpenGL graphics software will be re-tooled to take advantage of new dual-core processors which will "increase, or in some cases, even double the performance of OpenGL-based applications".

Ruby On Rails, a program for creating web-based applications, will ship with the server versions of Leopard. Apple is hoping that this will increase the development of web-based applications by Mac developers.

The vendor plans to release a new Xray tool that allows developers to monitor the resources that their applications use and resolve potential bottlenecks. The software is based on the open source Dtrace tool developed by Sun Microsystems. 

Apple unveiled some OS X 10.5 features at its World Wide Developer Conference in August. Leopard is currently available only as a pre-release to members of the vendor's Apple Developer Connection programme.