Like PIL, Pillow is `licensed under the MIT-like open source PIL Software License <https://raw.githubusercontent.com/python-pillow/Pillow/master/LICENSE>`_
PIL is not setuptools compatible. Please see `this Image-SIG post`_ for a more detailed explanation. Also, PIL's current bi-yearly (or greater) release schedule is too infrequent to accommodate the large number and frequency of issues reported.
As more time passes since the last PIL release, the likelihood of a new PIL release decreases. However, we've yet to hear an official "PIL is dead" announcement. So if you still want to support PIL, please `report issues here first`_, then `open corresponding Pillow tickets here`_.