This paper examines the recent smartphone war between Samsung Electronics and Apple Computers. By pioneering the smartphone, Apple opened a new horizon in the mobile phone industry. Samsung, a latecomer in this segment of the market, belatedly yet rapidly pursued Apple. Nokia, formerly an ironclad leader in the communications and information technology industry, fell behind. In this study,key success factors of the smartphone industry are found to be totally different from those of the feature phone industry. Samsung and Apple compete intensively for the critically important software portion of the market. Platform leadership and industry ecosystems are particularly highlighted in this analysis of the smartphone war. Relationships between smartphone manufacturers and operating system developers are also discussed, and comments on patent litigation are provided.