Shoot, much of the Go lang team came from Plan 9. And they brought a lot of code and ideas with them.

Currently on my mind os `os.FileMode`; here's a comment I wrote in some Go code that interfaces with Python:

    // 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

PS: If you weren't aware, Renée French's connection to Plan 9 and Go is largely that she's married to Rob Pike.