Saying that Firefox "need[s] to be where [its] users are," it appears that Mozilla is going to produce a version of Firefox for iOS.
Mozilla is having a large, week-long working and meeting event in Portland, and TechCrunch spotted a couple of tweets coming from Mozilla employees talking about bringing Firefox to iOS. Mozilla Release Manager Lukas Blakk tweeted that Mozilla was going to get Firefox on iOS because that's where its users are. Manager of Data Science Matthew Ruttley tweeted, "Firefox for iOS!! Let's do this!!!" (exclamation points all his), and he accompanied the tweet with a photo of a presentation that included a picture of an iPhone.
In a brief statement confirming the tweets, Mozilla has announced that it is experimenting with "something that allows iOS users to be able to choose a Firefox experience."
As recently as March 2013, Mozilla ruled out bringing Firefox to iOS due to the technical restrictions that Apple imposes on its platform. Then, as now, Apple effectively prohibits the creation of high-performance browser engines on its smartphone operating system through a number of technical restrictions. The only option browser developers have had is to embed Apple's own WebKit and provide a custom user interface around that.
Prior to the release of iOS 8, even this option was unappealing, as the embedded WebKit did not have access to the high-performance JavaScript engine that the built-in Safari includes.
While the former restriction hasn't been lifted, iOS 8 allows the embedded WebKit to use the full-power JavaScript engine, and as such, it means that third-party browser front-ends no longer operate at a performance disadvantage relative to Safari. Using Apple's WebKit—as Google has done with its Chrome for iOS—still allows Mozilla to plumb in its own interface, password and bookmark syncing, and other features. This will give Firefox users the same kind of cross-platform experience that users of some other browsers enjoy.