As background, Japan's top mobile provider DoCoMo announced in 2003 that it would adopt Linux as the OS for its 3G (third-generation) mobile phones. It had fallen behind competitor KDDI in the 3G market, and felt that standardizing on a single OS might help it catch up.
In response, NEC and Panasonic decided in 2004 to collaborate on a Linux OS. Built on a MontaVista kernel, and running an application stack dubbed "MOAP" (Mobile-Oriented Application Platform), the stack went on to power five generations and counting of Linux phones that are sold mainly for use with DoCoMo's "FOMA" (Freedom of Mobile Information Anywhere) 3G Internet services.
The agreement worked so well that in 2006, Panasonic Mobile Communications and NEC decided to formalize the partnership through a joint venture called Esteemo.
Initially capitalized at 100 million yen (then about $845,000, but now closer to $900,000), the venture would be tasked with creating a common hardware and software platform for mobile handsets, the companies said at the time.