Extremely promising new Python NLP tool: spaCy (commercial open-source software):
Unfortunately, it is only able to deal with English input at the moment and installation on Windows seems to be tricky. The project is currently under intense development and it will be interesting to check the following links on a regular basis:
License: AGPLv3 (free for open-source projects), changed to MIT License (27 Sep 2015)
Source: http://spacy.io/index.html#detailed-speed-comparison [accessed: 24/07/2015]