Online Summarizers overview

There is also TextTeaser (https://github.com/MojoJolo/textteaser). There is a version in Python and Scala. I believe is behind the article summarization bots on reddit.

I explored using it to generate talk summaries for https://www.findlectures.com and have been reasonably happy with it, although it's tough to get a summary that is succinct enough for search engine results.

One of the best summarizers not mentioned: https://slack.com/apps/A2B487WT0-sumbot