The Semantria Python SDK by Lexalytics allows API interaction to access semantic web features. Sentiment analysis, keyword extraction, and word classification are some of the capabilities that developers can implement into applications.
Our API directory now includes 22 sentiment APIs. The newest is the Bitcoin Sentiment API. The most popular, in terms of mashups, is the Klout API. We list 7 Klout mashups. Below you'll find some more stats from the directory, including the entire list of sentiment APIs.