iOS 11 is now running on 59 percent of iPhones and iPads, according to Apple, which has updated its developer support page with the new data.
Apple also said that as of 4 December, another 33 percent of devices were running on iOS 10, and eight percent were powered by earlier versions of the operating system.
The latest version of iOS became available in late September, and in November Apple said it was running on just over half (52 percent) of devices, while 38 percent were still on iOS 10 (which arrived in September last year) and 10 percent on earlier versions.
Now that the iPhone is ten years old there has been a certain amount of fragmentation -- iPhones older than the iPhone 5s can't run the latest operating system, for example. iOS 11 is probably seeing a slightly slower uptake than for previous versions of iOS, but because Apple controls both the hardware and the software it has managed to keep users updated at a decent rate.
In contrast, only 0.3 percent of Android devices are running Android 8 Oreo, which became available in August this year.
Around 20 percent are still on Android 7 Nougat, and about 30 percent are still on Android 6 Marshmallow and slightly less (27 percent) are still using Lollipop -- version 5, which was released back in 2014.
Not all older Android hardware can run the newest version of the OS, but Android hardware makers are often less interested in updating older hardware than selling new devices.
Apple's mobile OS signals a clear shift in emphasis towards greater productivity on the iPad, as well as flagging up the company's ambitions in augmented reality and home automation.
A lot of bug fixes and tweaks, and a few new features.