The pytest-xdist plugin extends py.test with some unique test execution modes:

  * Test run parallelization: if you have multiple CPUs or hosts you can use
    those for a combined test run. This allows to speed up development or to
    use special resources of remote machines.
  * --boxed: (not available on Windows) run each test in a boxed subprocess
    to survive SEGFAULTS or otherwise dying processes
  * --looponfail: run your tests repeatedly in a subprocess. After each run
    py.test waits until a file in your project changes and then re-runs the
    previously failing tests. This is repeated until all tests pass after
    which again a full run is performed.
  * Multi-Platform coverage: you can specify different Python interpreters
    or different platforms and run tests in parallel on all of them.
