more (documentation about?) options

[ajschumacher]

from Panos:

I have been using mainly NLTK for my teaching, but also OpenCalais (btw, there is also a Python interface at https://code.google.com/p/python-calais/)

There were also a few other APIs that perform NER and also connect the references to the Linked Data (e.g, TextRazor https://www.textrazor.com/named_entity_recognition and Alchemy http://www.alchemyapi.com/api/linked-data-support) but they are paid and they may not scale well in terms of cost.