This is a Tox plug-in that allows you to tag test environments and then easily select a subset of test environments when running Tox.
The plug-in and its rule system is heavily inspired by nose-attrib.
Here's an example:
[tox] envlist = py27-win, py27, py34, [testenv:py27-win] tags = win
Then, you can easily run only the
$ tox -t win
You can also run all but the
$ tox -t '!win'