Plan 9 from Bell Labs(github.com)

  It looks like Plan 9 failed simply because it fell short of being a compelling enough improvement on Unix to displace its ancestor. Compared to Plan 9, Unix creaks and clanks and has obvious rust spots, but it gets the job done well enough to hold its position. There is a lesson here for ambitious system architects: the most dangerous enemy of a better solution is an existing codebase that is just good enough.
  — Eric S. Raymond

    // A StatMode represents a file's mode and permission bits, as represented in Python
    // (i.e. `os.stat()`'s `st_mode` member).  Similar to how Go's `os.FileMode` assigns bits to have
    // the same definition on all systems for portability, Python's `stat` assigns bits to have the same
    // definition on all systems for portability.  And it just so happens that Go's bits match those of
    // Plan 9, and Python's bits match those of the Linux kernel.
    type StatMode uint16