Apple CEO Tim Cook delivers his keynote address at the Worldwide Developers Conference in San Francisco, California June 8, 2015.[Photo/Agencies]

Here are some of the highlights on Apple's latest software updates at the 2015 WWDC.

OS X El Capitan

"OS X delivers unparalleled integration between Mac hardware, iOS devices, apps and online services, and has helped Mac sales outpace the PC industry every year for the last decade," said Federighi.

"Customers loved last year's landmark OS X Yosemite release and made it the fastest-adopted PC operating system ever. With El Capitan, we're further refining the Mac experience with enhancements to window management, Spotlight and built-in apps, and improving performance so everyday activities -- from launching apps to accessing email -- are faster and more responsive."

According to Apple, the developer preview of OS X El Capitan is available to Mac Developer Program members starting Monday. Mac users can participate in the El Capitan Beta Program in July and download the final version for free from the Mac App Store this fall.

iOS 9

"iOS 9 is packed with more intelligence throughout, and delivers big updates to the apps customers use most -- Maps supports public transit, a redesigned Notes app provides great new ways to capture ideas, and a beautiful News app delivers content that's personalized to your interests," said Federighi.

According to Federighi , with the new multitasking iPad features, users can take advantage of the power of iPad, working in two apps at the same time with Split View, Slide Over or Picture-in-Picture.

WatchOS 2

WatchOS 2, the first major software update for Apple Watch, unveiled during the WWDC, giving developers the tools to build faster and more powerful apps running natively on Apple Watch.

According to Apple, starting Monday, developers can take advantage of innovative hardware features of Apple Watch including the "Digital Crown", "Taptic Engine" and heart rate sensor, along with software APIs to build new app experiences.

"We are thrilled with the feedback we're getting from Apple Watch customers, and after just a few weeks of availability we're excited for developers to start building native apps for watchOS 2," said Kevin Lynch, Apple's vice president of Technology.