For quite a while, Cocos2d-iphone was the engine for indies to develop games for the iPhone. I think it really had an impact in the early life of the App Store, and was an incredible tool for developers (at least for me and our company). It's free, open-source, very indie-friendly, and just overall wholesome! Now, it seems the iOS-centric version of Cocos2d is slowly dying (Cocos2d-x is continuing on a separate path). Except, the main maintainer of the Objective-C version of Cocos2d for the past couple of years wants to develop a cross-platform Swift version of Cocos2d. If the Kickstarter fails, that'll probably be it for the iOS centric version of the engine. I'm not sure how good an idea it is to do a Swift version, but my impression is that the guy doing the Kickstarter is a solid developer. We don't use Cocos2d anymore (switched to Unity), and I have no affiliation with the project whatsoever, but it'll be a sad thing if the iOS-centric version of Cocos2d dies, so I just wanted to share it here in case some other nostalgic people who've benefitted from Cocos2d over the years also want to pitch in http://forum.cocos2d-objc.org/t/pureswift-kickstarter-status-updated-dec-20/17804 https://www.kickstarter.com/projects/1455832115/cocos2d-pureswift
We backed this kickstarter since we made Yukon Warrior, Furdemption, and Furdemption 2 (in progress) using Cocos2d. Unless something big happens with cocos, we're probably moving to Unity at some point.
We've also moved to Unity, mainly for 3d and cross-platform, but made a contribution because of the immense use we've gotten out of Cocos in the past. I think it'd be still useful for certain people to have an open-source engine though. I just started playing Furdemption after seeing this by the way, it's very fun!