Complex sentence: While many other handset makers tended to focus on supporting one or two operating system, Samsung for a time kept supporting a wider range, like Symbian, Windows Phone, Linux-based LiMo, and Samsung's proprietary Bada.
Split into simpler sentences: While many other handset makers tend to focus on supporting one (or at most two) operating system, Samsung has kept supporting a wide range of operating systems in the market. Samsung also supports other competing operating systems such as Symbian, Windows Phone, Linux-based LiMo, and Samsung's proprietary Bada.