Or pijul.
51 karma · joined October 2, 2016
berkley's summarizer takes syntax trees of sentences and cuts off unimportant adjectives (or these unimportant brackets, or comma separated explanations etc.) directly from sentences (since operations are done on syntax trees the shortened sentence is gramatically correct, if parsed syntax tree is correct).
it also uses coreference resolution. (for example, if you were to take the last sentence without context you wouldn't know what/who "it" is, they build up a map of named entities [name - Berkeley Document Summarizer] and replace any pronouns (if necessary) with the names to which they refer.
summarizing quality should be much better than the reddit bot.