SAN FRANCISCO (AP) -- Apple CEO Steve Jobs briefly emerged from a medical leave Monday as the company announced new software that makes Mac computers behave more like mobile devices.
He received a standing ovation as he appeared at Apple Inc.'s annual developers' conference, his second major public appearance since he went on medical leave in January for unspecified reasons and duration.
James Brown's "I Feel Good" played over the loudspeakers just before he walked on stage, looking thin, in his signature outfit of mock turtleneck and blue jeans.
One audience member shouted out, "we love you."
Jobs unveiled an operating system update for Mac computers called Lion. With it, Apple is expanding the ways finger-touches can be used to control the software. For instance, with the swipe of the fingers over the Mac trackpad, the user can switch from one program to another.
In another nod to bringing the computer closer to the iPhone and iPad, Apple is adapting more of its programs to run in a special full-screen mode, in addition to the traditional "window" mode.
Lion will be available to consumers next month for $30. A preview version was made available Monday to software developers.
Jobs made a public appearance in March to announce a new iPad. On Monday, Apple said it has sold more than 25 million iPads since they went on sale 14 months ago.
Jobs was also expected to announce a new service called iCloud.
ICloud will apparently allow customers to store their music online. The company has been in talks with the major recording companies to make this possible.
ICloud could give users a wide array of music for their iPhones, iPads and Wi-Fi-capable iPods, without having to connect them to their home PCs to transfer songs. Google Inc. and Amazon.com Inc. have launched similar services.