The Stanford NLP Group's Sentiment Analysis tool is a free, web based live demo based on a sentiment analysis treebank, trained to predict the sentiment in movie reviews. Users can test out the sentiment analysis model with their own text in the box provided. The dataset and code is available for download, and the sentiment analysis model is now integrated into Stanford CoreNLP.
Comments
The live demo is currently down.
More information can be found in the following pages:
https://nlp.stanford.edu/sentiment/
https://nlp.stanford.edu/sentiment/code.html
The current model is integrated into Stanford CoreNLP as of version 3.3.0 or later, which is still downloadable on the website.