There's a comment above that links to the repos for the source code, but it looks like it uses the python package Sumy to do the summaries. https://pypi.python

There's a comment above that links to the repos for the source code, but it looks like it uses the python package Sumy to do the summaries. https://pypi.python.org/pypi/sumy https://pypi.python.org/pypi/sumy