Apple has apparently planning to come up with public beta version of iOS 8.3 and iOS 9 according to the source. This information comes from multiple sources which quotes both iOS 8.3 and iOS 9 beta version will be released for public. If that happens this would be the first ever public beta release.
iOS 9 Public Beta
So why so hurry in releasing iOS 9? We assume it's because of bad reputation of iOS 8 that it got with bugs and stability. We can easily say that it wasn't the Apple's smoothest release and plan of coming out with public beta release is to include general public involved so that they can collect more number of errors, bugs and problems currently on iOS 8, 8.1 and 8.2. Once the list of bugs is collected, Apple will work out to fix those issues on bigger note with official iOS 9 build. Keeping that in mind, iOS 9 will have a long list of changelog apart from improvements in the update.
There is also planning for releasing the 8.3 public beta and it should be out in mid-March. iOS 9 will be releasing at Apple's Worldwide Developer Conference in June 2015 and so we can easily assume public beta release late in the summer with final build scheduled for releasing in fall.
Via : 9to5Mac