LINUX runs the Google servers that manage billions of searches each day. It also runs the TiVo digital video recorder, the Motorola Razr cellphone and countless other electronic devices. But why would anyone want to use Linux, an open-source operating system, to run a PC? “For a lot of people,” said Jim Zemlin, executive director of the Linux Foundation, “Linux is a political idea — an idea of freedom. They don’t want to be tied to Microsoft or Apple. They want choice. To them it’s a greater cause.”