Apple Inc. (Nasdaq: AAPL)  is releasing a fresh lineup of computers and software tools to woo consumers and keep developers making applications amid accelerating rivalry from Google Inc. (Nasdaq: GOOG), Microsoft Corp. (Nasdaq: MSFT) and, now, Facebook Inc. (Nasdaq: FB).

Apple will use the Worldwide Developers Conference starting today in San Francisco to debut Mac computers with high-definition screens, as well as features for the software that powers its iPhone and iPad. Phil Schiller, Apple’s senior vice president of product marketing, will probably emcee the keynote.

Leadership in the consumer-electronics industry hinges on a company’s ability to get developers to put its products first when building the next big application, such as “Angry Birds” or “Shazam.” With more than 600,000 downloadable games, magazines and productivity tools, Apple is the application leader.

Microsoft is playing catch-up before the release of its next operating system, Google will host a developers conference this month and Facebook just opened its own store.

“It’s not just a battle for consumers’ hearts and minds — it’s a battle for developers to get that next great application to be available first and foremost on their platform,” said Charles Golvin, an analyst at Forrester Research Inc. who studies the mobile technology industry. “These companies are duking it out.”

The success of Apple’s App Store has helped create an economy for downloading mobile applications that will reach $58 billion in sales in 2014, according to Gartner Inc. More than 25 billion apps have been downloaded from Apple’s store, and developers have received $4 billion from the sales, according to Cupertino, California-based Apple.

Bigger iPhone

Facebook is the latest to join the mobile app-store craze, opening an online bazaar last week. The Google Play store boasts more than 500,000 apps, while Microsoft has lined up design firms, recruited interns and sent engineers on an around-the- world road show to line the shelves of its app store.

At this week’s event, Apple will probably signal a bigger screen for the next iPhone, its best-selling product, by telling developers to write future applications that can work on a larger surface, said Andy Hargreaves, an analyst at Pacific Crest Securities Inc. in Portland, Oregon.

Apple also plans to announce a deal that lets users quickly post pictures and other content from phones and tablets to the profiles on Facebook Inc.’s social network, people with knowledge of the matter said.

Trudy Muller, a spokeswoman for Apple, declined to comment, as did Derick Mains, a spokesman for Menlo Park, California- based Facebook.

Cook’s Turn

Last year’s event, where co-founder Steve Jobs introduced Apple’s iCloud service, was the last Apple event he led before he died in October. He had used previous conferences to introduce such products as earlier iPhone models.

This year’s conference, running June 11-15, will give Chief Executive Officer Tim Cook a chance to outline his vision for why developers should continue to build for Apple rather than competitors, said Carl Howe, an analyst at Yankee Group.

Developers will look for signs that Apple will announce added uses for Siri, its voice-recognition technology, said Corey Reese, the CEO and co-founder of Ness Computing Inc.

“Everybody in the industry pays very close attention to what direction they go,” said Reese, who will be attending the event and whose company makes an application that provides restaurant recommendations.

Apple will use the event to introduce a new mapping application that would replace Google Maps, which it has used since 2007, a person familiar with the plans said.

Google Standoff

The change may help shunt advertising revenue toward Apple and away from Google, said Forrester’s Golvin. Apple also is adding Baidu Inc.’s search engine as an alternative to Google for iPhone users in China, people said last week.

The changes highlight Apple’s growing rivalry with Google, which has joined companies including Samsung Electronics Co. to challenge the iPhone and iPad. Smartphones running Google’s Android operating system accounted for 56 percent of global sales in the first three months of the year, compared with 23 percent for the iPhone, according to Gartner. Google hosts its own developers conference at the same location in San Francisco June 27-29.

At today’s event, Cook and other Apple executives also will showcase the latest lineup of Mac computers, including MacBook Pro laptops that will sport high-definition screens and speedier chips made by Intel Corp., people familiar with the plans said last month.

Outpacing Hewlett-Packard

Releasing the new computers puts Apple ahead of rival PC makers such as Hewlett-Packard Co. and Dell Inc., which will introduce machines later in the year to work with Microsoft’s coming Windows 8 release.

After today’s announcements, starting at 10 a.m. in San Francisco, the weeklong event is closed to the public and media. Developers pay about $1,600 apiece to attend and spend the week meeting with Apple engineers to learn about new features that are being introduced and how they can integrate them into their applications. More than 5,200 people attended Apple’s developers conference last year.

“This is when Apple releases their information and it’s the one time of year when you know you’re going to get more of an idea about what they are up to,” said Matt Murphy, a partner at Kleiner Perkins Caufield & Byers, which invests in companies that make mobile applications.