Apple is holding its annual developers’ conference this week. For complete coverage of the first day of the event, keep reading.

The conference in San Francisco, which Apple calls the Worldwide Developers Conference, will be carefully watched, since the company has not made a major product announcement in half a year. Monday, however Apple announced a redesigned operating system called OSX Mavericks, reports Hayley Tsukayama:

[Senior vice president Craig] Federighi described Mavericks as a redesign really meant for power users, adding smoother support for multiple displays and adding organization features such as tabbed browsing in the Finder and the ability to tag files. ¶ Tagging works much like it does in the online world. Users can give files any sort of designation they want, such as important, in progress, presentations, etc., and can search for files using those tags. ¶ Federighi also highlighted several features within the new system aimed at reducing power consumption, to extend the battery life on its computers. For example, non-active apps are put into a “napping” mode that reduces background computer activity and, therefore, power drain.

In addition, Apple outlined improvements to its MacBook Air line. The new laptops will feature faster processors and extended battery life. The company also outlined a new streaming music service, iTunes Radio, which will be free with advertisements:

Similar to Pandora, the program lets users look up songs or artists they like and create radio stations based on that preferred music. Users can offer some input into the way the radio station chooses music by liking or disliking individual songs. ¶ Apple said users will be able to share their stations with their friends and buy songs with one click from the iTunes store. The company will also be showing “featured stations” that pull in music from what is trending on Twitter at the moment.

Listen to Tsukayama discuss Apple and the market for streaming music below:

Apple officially entered the streaming music market with its announcement of iTunes Radio at its Worldwide Developers Conference on Monday. The Post’s Hayley Tsukayama reports on why the new service could shake up the industry. (Jayne Orenstein/The Washington Post)