OS X 10.8 Mountain Lion hits the Mac App Store in July for $19.99

Developers will be provided on Monday with what Apple said is a near-final preview build of OS X 10.8. New features and details about Mountain Lion were revealed at the Worldwide Developers Conference keynote in San Francisco.

In addition, users who buy a new Mac between now and when Mountain Lion goes on sale will receive a free upgrade to the latest version of the operating system when it hits in July.

Apple highlighted on Monday the closer integration that OS X Mountain Lion will have with iCloud. For instance, the Notes and Reminders application will sync with the cloud-based service to allow access from anywhere with an Internet connection. The company also revealed that OS X 10.8 will get the voice dictation service, though it won't get the full Siri voice assistant yet.

Another new feature in Mountain Lion unveiled by Apple on Monday is Power Nap. Macs in Power Nap mode will stay up to date while operating in a power-efficient capacity. It is compatible with the second-generation MacBook Air and the next-generation Retina Display-equipped MacBook Pro.

As promised, Apple released the fourth Developer Preview for Mountain Lion on Tuesday. Though the release is close to being finalized, people familiar with Apple's documentation for the release reported that known issues that remain in the software include trouble entering a Wi-Fi password, an incorrectly-displayed login window for some systems with FileVault enabled and problems with some AMD and NVIDIA graphics cards. The OS X version of Game Center also still has several known issues.