Now I don’t have a master’s degree in Natural language processing, and you just might need one to get your hands dirty with this API. I see the text-processing.com API as offering a mid-level utility for incorporation in a web app. You might take text samples from your source, feed them through the Text-Processing API and analyze those results a bit further before presenting anything to your user.
Did you know that leraar is a Dutch word? A new API, LangID can help you with those pesky language identification problems. Feed it a string of text and the API returns the name of the language, its ISO code and even an image of the flag for a country that speaks the language (the latter could be a hot-button political issue--watch out). You can choose your output as either XML or browser-friendly JSON. (More details at our LangID API profile.)