How do you parse a paragraph of text into sentences? (perferrably in Ruby)

Try looking at the Ruby wrapper around the Stanford Parser. It has a getSentencesFromString() function.

Just to make it clear, there is no simple solution to that. This is topic of NLP research as a quick Google search shows.

However, it seems that there are some open source projects dealing with NLP supporting sentence detection, I found the following Java-based toolset:

openNLP

Additional comment: The problem of deciding where sentences begin and end is also called sentence boundary disambiguation (SBD) in natural language processing.

ruby text parsing split nlp

Looks like this ruby gem might do the trick.

CodeHunter