Apple's 26th Worldwide Developers Conference had attendees from 70 countries.
80 percent were there for the first time, with over 1,000 engineers from Apple on-hand to watch their executives present and answer question from developers.
Apple's current operating system, OS X Yosemite, has 55% of active Mac users on its latest update, which Craig Federighi, Apple's senior vice president of software engineering, called "the fastest adoption rate of any PC operating system ever."
At last year's conference, Apple said that over 50% of users were on Mavericks, the previous version of OS X.
83% of iOS users are on the latest version of the operating system, Federighi said.
Siri, Apple's personal assistant app, gets 1 billion requests every week, Federighi said.
It's also 40% faster.
Apple Pay will work at over 1 million locations in July, said Jennifer Bailey, the head of the Apple Pay business.
In March, Apple CEO Tim Cook said that Apple Pay was accepted at more than 700,000 locations.