The World Wide Developer Conference (WWDC) 2015 took place in San Francisco with attendees from over 70 countries, primarily featuring first-time attendees. Key announcements included updates on OS X El Capitan, iOS 9, and watchOS 2, highlighting new features such as multitasking on iPad, advanced app capabilities, and improved graphics performance. Significant enhancements in development tools, particularly Xcode 7 and Swift 2, were also showcased, emphasizing app optimization and testing advancements.