There are a number of mobile operating systems, but five major players have floated to the top, dominating a major chunk of the market. It used to be that people chose their phone only by their carrier and what brands they offered. Today many choose their phone based on the manufacturer and its operating systems features.

Symbian: 31% of all mobile phones run this open-source operating system, most of which are “feature phones,” otherwise known as dumb phones, as opposed to smartphones. Nokia is the largest shareholder and customer. Other brands whose phones run Symbian include Fujitsu, Samsung, Sharp, and Sony Ericsson.

Symbian’s worldwide market share has declined from over 50% in 2009 to about 30% in 2010. Last month, Nokia announced a partnership with Microsoft, which will replace Symbian OS with Windows’ operating system.

Windows Mobile 7: Less than 5% of all mobile phones run Windows Mobile 7, which took over where Windows Mobile left off. This is a closed-source operating system that can be managed through Microsoft Exchange. Microsoft’s mobile industry market share has recently slipped quite a bit, leaving the future of Windows Mobile 7 uncertain.

BlackBerry RIM: BlackBerrys running this closed-source operating system make up 15% of all mobile phones. BlackBerry RIM began as an enterprise solution, and still is for the most part, but a consumer base has developed. Businesses like BlackBerry RIM because enhanced end-to-end encryption is standard with BlackBerry Enterprise Server. BlackBerry RIM meets the Department of Defense’s requirements, and it’s good enough for the President. This system supports over 15,000 applications, and over two million are downloaded daily.

Apple iOS: 16% of all mobile devices are iPhones or iPads running Apple iOS. This is a closed-source operating system. Currently, Apple iOS supports over 400,000 applications, including third party applications as of July 2008, which have been downloaded over 10 billion times.

Google Android: 33% of all phones run Google Android, an open-source, Linux-derived operating system backed by Google, along with major hardware and software developers that form the Open Handset Alliance. (Intel, HTC, ARM, Samsung, Motorola, and eBay, to name a few.) Google operates the official Android Market, which contains over 150,000 applications, with an estimated 3.7 billion downloads.

In summary, I’ve had plenty of Symbian-based phones, but at this point, I’ll may never have one again mainly because they are more feature than smart. I’ve never had the type of job that requires a BlackBerry. Many love the Android operating system, and though it has its detractors, I do love Google and may consider Android. But for now, I’m still in awe of my iPhone.

Robert Siciliano is a personal security expert contributor to Just Ask Gemalto. (Disclosures)