SAN FRANCISCO—Apple Inc. sought to recapture its authority as a tastemaker, unveiling the biggest redesign in iPhone software since the smartphone was introduced in 2007 and stressing that the company hasn't lost its cool.
The more minimalist mobile software, along with new Mac hardware and a streaming radio service, energized the thousands of developer attendees who attended the kickoff keynote address for Apple's Worldwide Developers Conference in San Francisco.
But the updates left some consumers and developers wanting more dramatic changes, such as payment capabilities or bigger improvements to Apple's online services.
Phill Ryu, a longtime Apple fan and designer who runs app-design studio Impending, said he liked the new direction, but Apple's "online services are lagging more and more behind the state of the art by Google . I'm not sure Apple can continue making up for that by continuing to squeeze out more gains from design."
Apple executives came out swinging against those who question whether the company, which hasn't released a major new product since last year, has lost its cool.
"Can't innovate any more, my a—," said Apple's marketing chief Phill Schiller, as he unveiled a new, cylinder-shaped Mac Pro computer expected to be released later this year.
Investors, whose faith in Apple has waned in recent months, brushed off the announcements, many of which had been previously reported. Apple shares closed down less than 1% to $438.89. This year, the stock is down about 18%.
Monday's event was a potpourri of announcements across Apple's product lines. They included new laptops, a version of iOS to run in cars, a new Mac operating system and a music service known as iTunes Radio.
The new software included revamped apps with more white space and neutral colors, as well as a new "control center" swipe menu and new ways to shares photos with people around you.
Many of the updates are designed to cement developers' and consumers' loyalty to Apple, a key factor in helping it maintain momentum and defend its base against competition from Samsung Electronics Co. and other manufacturers.
But Apple also took aim at competitors, the latest illustration of how cutthroat the technology business has become and Apple's desire to control its own destiny.
Apple said that Microsoft Corp.'s Bing search engine would replace Google Inc. as the default search provider for its Siri voice-activated assistant, the latest step to distance itself from its rival. Apple also released a new version of its iWork productivity software that runs online, in a challenge to both Google and Microsoft. And the company unveiled new photo-organizing and sharing features to compete with apps like Facebook Inc.'s Instagram.
The event was also a chance for Apple Chief Executive Tim Cook to respond to critics who contend Apple's pace of innovations has slowed and to re-emphasize the company's focus on design.
Indeed, that primacy of design has long been core to Apple's identity but has taken on new urgency as competitors catch up on hardware designs and features, and as the iPhone and iPad mature.
Mr. Cook wrapped-up the event by playing a new television ad on how Apple thinks about design, a change for a company that generally advertises specific products. In describing the new iOS design, Apple Senior Vice President Jonathan Ive said it defined "an important new direction and in many ways a beginning."
Alex Fish, developer of a photo-sharing app called Rando, said he liked that Apple made it easier for users to move their activities from one Apple device to the next. "It brings the whole family of devices together," said Mr. Fish.
Some analysts questioned whether the new products and features were enough to put Apple back on track.
"Apple made a play for its customers' emotions, but they didn't necessarily stoke any new consumer behavior," says Forrester Research analyst James McQuivey, adding that he doesn't think people are going to run to buy Apple devices after the news. "They have shown Apple's style, but the sum total doesn't suggest that Apple has its mojo back."
The real referendum on the announcements will come this fall, when the software will be released to consumers. Apple is also expected to release its latest iPhone in the fall, which is expected have similar hardware to the iPhone 5, people familiar with the matter say.
The new mobile operating system will also run on older iPhones, meaning Apple faces a high bar in getting consumers to upgrade to new hardware that is similar, analysts say.
In the fall, Apple will also release a new Mac operating system, as its mobile and desktop operating systems continue to converge.
The new software is dubbed "Mavericks" in reference to a surfing spot in Northern California, ending Apple's practice of naming its Mac software updates after big cats.
Earlier in the keynote address, Craig Federighi, who runs Apple's Mac and mobile software groups, showed off features of "Mavericks" including new ways to handle multiple windows and screens, as well as new power-optimization features.
<By JESSICA E. LESSIN and GREG BENSINGER >