Python 3 support graph for the 360 most popular Python packages!
This site shows Python 3 support for the 360 most downloaded packages on PyPI:
There can be many reasons why a package still does not support Python 3.
If you are package maintainer, it's time to start porting (if you haven't already). Here is an in-depth guide Porting to Python 3 and the official porting HOWTO. If you are not able to give the time needed, please seek for help from the community by announcing your need for help on blogs, IRC, mailing lists, etc.
If you are user of the package, send a friendly note to the package maintainer. Or fork it, and send a pull request to help move the project towards Python 3 support.
This site utilizes a little tool, caniusepython3, created by Brett Cannon. Throw your requirements.txt file at it and it will tell you which packages support Python 3, and list out which don't. If you want to know how the site works, see README.