The iPhone 2.0 platform includes an SDK (software developer kit), with native APIs (application programming interfaces) for developers to write mobile applications for the iPhone. Using the SDK, developers can write applications for location-based services, like photoblogging or to connect friends over social networks. The SDK's rich-media layer provides resources for developing 3D games and writing programs for audio and video playback on the iPhone. The SDK also allows development of database and touch-based applications.

During the keynote, companies demonstrated applications for the new iPhone, including Typepad, which has written an application to allow photoblogging. MLB.com demonstrated an iPhone 2.0-based program that shows video highlights of Major League Baseball games. Using the SDK, Modality has created a medical application that provides students with image and text-based reference content on human anatomy.

The iPhone 2 platform will be available as a free download in July. Developers will be able to sell their third-party iPhone applications through Apple's online App Store, which will be accessible by users in 62 countries.

Users will be able to download iPhone applications under 10M bytes over cellular networks, by Wi-Fi or through iTunes. Applications over 10M bytes will be available only through Wi-Fi or iTunes. Users will also be able to distribute applications by syncing iPhones.

The software platform also adds full contacts search, a calculator, improved language support and parental controls to for data access to iPhones, Jobs said.

"Some teenagers may not like this, but that's the way it is going to have to be," Jobs said.

The software platform will enable the entry of Simplified Chinese and Traditional Chinese and two forms of the Japanese language to iPhones. Users will also be able to view Microsoft Office (Word, Excel and PowerPoint) and Apple iWork (Pages, Numbers and Keynote) productivity documents on the iPhone.

Apple also announced MobileMe, a service to push e-mail and synchronize information wirelessly on the fly. Storing information on a "pod," MobileMe immediately pushes updated e-mail, contacts and calendars to devices, including cell phones and laptops. Users will be able to use the service on cell phones or through the Web site at Me.com. Users will also be able to transfer and share images and other documents. MobileMe replaces Apple's .Mac online service. Users using .Mac will be automatically upgraded to MobileMe, Apple said.