Changelly is a cryptocurrency exchange founded in 2013 and based in Prague. They offer a simple interface for exchanging between cryptocurrencies. You can also buy cryptocurrencies via credit card although the fees for this are higher.
Changelly is more like a traditional currency exchange than a fully featured trading website. You need to provide an email address to register and transactions take an average of 5-30 minutes. They claim to offer over 70 cryptocurrencies although availability does vary.