Dennis Callaghan, an analyst at The 451 Group, likes what rPath is doing, though he noted that the company has "a pretty small niche and customer base at this point."

The marketing of open-source stacks won't disappear overnight, said James Governor, an analyst at Denver-based RedMonk, because their tidiness still appeals to some customers. But their rigidity will make them less relevant as more companies expect the true standards-based component modularity that service-oriented architectures promise, he said.