Apple announced on Monday that it will hold its annual Worldwide Developers Conference, where it has traditionally introduced the next generation iPhone, this year from June 6 through June 10 at San Francisco's Moscone West.

At this yearâs five-day conference, Apple plans to unveil the future of iOS and Mac OS, including demonstrations of the new kinds of apps that developers can build using Appleâs advanced frameworks and more than 100 technical sessions presented by Apple engineers.

"At this yearâs conference we are going to unveil the future of iOS and Mac OS," said Philip Schiller, Apple's senior vice president of Worldwide Product Marketing. "If you are an iOS or Mac OS X software developer, this is the event that you do not want to miss."

The news would suggest that Apple will not hold its annual April developer event, to preview the next major release of iOS, as it has done in years past. That would lend support to a new rumor that Apple may not release its new cloud-based iOS 5 upgrade until this fall. New major iOS releases usually coincide with the debut of a new iPhone in June.

At this year's WWDC, mobile developers will be able to explore the latest innovations and capabilities of iOS and learn how to greatly enhance the functionality, performance and design of their apps. Mac developers will see and learn how to develop world-class Mac OS X Lion applications using its latest technologies and capabilities.

Developers can even bring their code to the labs and work with Apple engineers, applying development techniques and best-practices to enhance their apps.

Activities at Appleâs WWDC 2011 include:

More than 100 technical sessions presented by Apple engineers on a wide range of technology-specific topics for developing, deploying and integrating the latest iOS and Mac OS technologies;

Over 1,000 Apple engineers providing developers with code-level assistance, insight into optimal development techniques, and guidance on how they can make the most of iOS and Mac OS technologies in their apps;

The opportunity to connect with thousands of fellow iPad, iPhone and Mac developers from around the world; and

Apple Design Awards which recognize iPad, iPhone and Mac apps that demonstrate technical excellence, innovation and outstanding design.