OS X El Capitan developer preview available today, public beta in July

Apple announced the next version of OS X, El Capitan, on stage at WWDC, and it will be available in preview form for developers today, with public releases coming later this year.
As a recap, OS X El Capitan brings some new Safari functionality, contextual search for Spotlight, improved graphics with Metal, and much more. Following on the developer preview today, OS X El Capitan will go into public beta in July, with a full release later this fall.