See the language usage breakdown of a User or Org right on their GitHub profile page.
GitHub User Languages is a simple extension that renders a pie chart onto a profile page on GitHub.
This pie chart shows a breakdown of the languages used in the public repositories owned by the User or Organisation.
The chart uses GitHub's official language colours for each language, and each segment can be clicked to take you to a list of the repositories owned by the account in each language.
Now you can see what languages a User or Org like to use all in a single place, right on their own profile!