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.
Google has dominated the search engine world for years, weathering the attempts of many competitors who have tried and failed to capture a piece of the search engine market. True Knowledge, a new natural language search service, is hoping to gain a piece of the search pie by harnessing the power of semantic data queries on the web.
Wolfram Alpha, the up-and-coming "answer engine" that we reported on back in May, has just released an API that developers have been awaiting since this spring. The new RESTful API provides access to the vast stores of data and computational knowledge available through the Wolfram Alpha project (technical details at our Wolfram Alpha API profile).