Apple on Monday kicks off its developers conference, where the focus will be on software in iPhones, iPads, iPods and Macintosh computers with scant hope for the next big thing.

In trademark style, Apple has remained mum about what it will unveil at the keynote presentation opening a sold-out World Wide Developers Conference devoted to tailoring applications or services for the company's coveted devices.

As is usually the case leading up to Apple events, rumors about what the California company may be planning have ricocheted across the Internet.

Public comments by Apple chief executive Tim Cook that the company will weigh into a new product category by the end of this year have added impetus to speculation that includes talk of a smartwatch or a system for using iPhones or iPads to control door locks, security systems and other computer-enlighted devices in smart homes.

"I think we will see bells and whistles from the developer perspective, but otherwise a low-key event," Gartner analyst Van Baker said of this year's WWDC in downtown San Francisco.

Apple will be keen to spotlight capabilities added to the operating systems powering its mobile devices and Macintosh computers, according to analysts.

- Developer devotion desired -

Apple, Microsoft and Google vie for devotion of third-party developers whose hip, fun or functional applications are essential to the popularity of smartphones or tablet computers.

Software features that Apple might crow about could include a mobile payments platform to challenge Google Wallet on Android smartphones, according to analysts.

Apple might also expand Passbook capabilities for storing and using digital airline tickets, movie passes and gift cards to include health-related information in a move that could tie to an "iWatch."

"While we might see some interesting extensions of iPhone, I am skeptical we are going to see anything groundbreaking," Forrester analyst Frank Gillett said.

"Think of this as their event for evolving the existing things they have -- new software but no important new hardware."

Apple could upgrade its line of Macintosh computers while it touts the next generation operating system.

The company has consistently preferred to spotlight big new products at stand-alone events surrounded by ample buzz.

- Dr. Dre could cameo -

The keynote speech, which will be webcast, is likely to include cameo appearances by music industry legend Jimmy Iovine and rapper Dr Dre, co-founders of Beats Music bought this week by Apple in a deal valued at $3 billion.

Apple's biggest-ever acquisition includes the maker of high-end audio equipment and a streaming music service, but more importantly, the talent of Beats brains Dr Dre and Iovine.

The wild card in the deal could be Iovine, 61, a Brooklyn native and son of a longshoreman who started in the business by cleaning studios and later was a recording engineer for John Lennon and Bruce Springsteen, before becoming a producer.

Iovine, a producer for U2, Dire Straits, Stevie Nicks, Patti Smith, Lady Gaga and Tom Petty and The Heartbreakers, is seen by some as a visionary for recognizing the trend of online streaming and subscriptions -- and away from Apple's model of purchasing individual songs online.

Iovine was key in helping persuade late Apple chief Steve Jobs in 2002 to launch the iTunes store, according to several accounts of Apple's history.

Yet for some, Apple's tie-up with a company best known for its high-end headphones is a mismatch.

Other analysts see more harmony in the deal for Apple, a pioneer in digital music that appears to have been overtaken by the successful models of streaming services like Pandora, Spotify and others.

Trip Chowdhry, analyst with Global Equities Research, said Beats can help Apple improve its iTunes Radio, which he called "a total disaster" while Beats offers "one of the best streaming music experiences."

Some say Beats could help Apple deliver wearable and smarthome products based on Beats designs.