December 17, 2009: Apple finally triumphs over longtime rival Microsoft … on mobile operating systems market share.

Figures released by research firm Comscore show that iPhone OS (as iOS is called at the time) surpasses Windows Mobile in the United States. At the time, roughly 36 million Americans own smartphones. Of these, a quarter run Apple’s mobile operating system.

Mobile phones mark turning point in tech

The undisputed leader at the time was Research in Motion’s BlackBerry operating system, found on 40% of U.S. handsets. Apple came in second. Microsoft took third, followed by Palm, then Symbian and (in last position) Google’s Android operating system.

In some ways, these adoption figures represented a turning point in tech. At the time, Microsoft led Apple in terms of market valuation, although clearly things were changing fast. Microsoft’s Steve Ballmer laughed at the iPhone, which he slated as a non-serious competitor to Microsoft’s Windows Mobile.

But by the following May, Apple overtook Microsoft in market capitalization, surpassing the tech giant that dominated Cupertino during the previous decade. By the end of 2010, Microsoft dropped its Windows Mobile operating system in favor of Windows Phone OS.

The long list of rival mobile operating systems from 2009 also sheds light on how much things changed in the years since. BlackBerry, then the industry leader, has become an afterthought. Palm OS and Symbian have been discontinued. Aside from iOS, the only other mobile OS to flourish is Android.

Mobile operating systems evolve

Figures from 2021 show that current U.S. smartphone operating system adoption breaks down like this: iOS runs on 58.5% of devices and Android on 41.2%. Other competitors command negligible percentages less than 1%. Things sure have changed in the past decade or so.

Which mobile operating system and handset were you using back in December 2009? Let us know in the comments below.