NASA is dropping Eucalyptus from its Nebula infrastructure cloud not only because its engineers believe the open source platform can't achieve the sort of scale they require, but also because it isn't entirely open source. NASA chief technology officer Chris Kemp tells The Reg that as his engineers attempted to contribute additional Eucalyptus code to improve its ability to scale, they were unable to do so because some of the platform's code is open and some isn't. Their attempted contributions conflicted with code that was only available in a partially closed version of platform maintained by Eucalyptus Systems Inc., the commercial outfit run by the project's founders.