The Internet is the main source of communication now-a-days; however, the identities of senders and receivers are not hidden. If someone wants to hide his/her identity, the most suitable choice is to use anonymous communication. Anonymous communication not only provides anonymity but also privacy. Anonymity is not something which was invented with the Internet. To overcome this and provide anonymity, anonymous communication systems were developed. In this paper a comparison of The Onion Router and Invisible Internet Project is presented. The Onion Router is the most deployed anonymous communication system that provides online anonymity and privacy while The Invisible Internet Project allows applications to send messages to each other pseudonymously and securely by using garlic routing.