Several variations of PDA operating systems exist. There’s RIM, Windows CE (also called Pocket PC), and Linux, among others. Palm is unique because of its command of the market: over 80 percent of PDAs run the Palm OS, according to market tracking firm NPD Intelect. Don’t assume this number includes PDAs from a single company. Sony, Handspring, and other vendors have licensed the Palm OS from 3Com, so you won’t lock yourself into the hardware of any single manufacturer.
Palm is also distinctive because of its history. First appearing in 1996, the release of the Palm OS marked the first commercially successful handheld OS. Many consumers now refer to any PDA as a “Palm,” regardless of the vendor. The implication for developers is similar to Microsoft’s dominance of the desktop market — if you want your desktop apps to reach the most consumers, you should target Windows. Likewise, if you want your handheld apps to reach the most consumers, you should target Palm.