There’s a believable scenario in which Intel x86 and ARM are the only processor architectures left by the end of the decade, in mainstream markets from cloud servers to mobile devices to the internet of things. But other contenders, like Power and MIPS, are determined not to go down without a fight. Both have set up open source foundations to ensure they are competitive in terms of software and support, and to reassure supporters that they still have convincing ecosystems and roadmaps. IBM created the OpenPower consortium last August, putting a great deal of its hardware and software into the open environment and signing up supporters including Google, Nvidia and Mellanox. Its main target is the emerging breed of low…