Nope. This isn't an April Fool's joke. There will come a time when you will be able to learn Klingon online. Duolingo just announced that they'll be carrying a Klingon course. For those who don't know, Klingon is the fictional language on Star Trek. It was created by Marc Okrand. According to Duolingo the language is quite direct and mixes in sense of humour and "plenty of insults." It revolves largely around "spacecraft, weaponry, and warfare." Of course, we don't have to tell the Trekkies that. But if this seems to be something you'd be interested in. You can have Duolingo let you know when the course is up. Now, if someone can teach me Sindarin, that would be awesome.