The Invisible Internet Project (I2P) is a garlic routing using overlay network and darknet that allows applications to send messages to each other pseudonymously and securely. Uses include anonymous Web surfing, chatting, blogging and file transfers. The software that implements this layer is called an I2P router and a computer running I2P is called an I2P node.
License: Open Source
The Advanced Onion Router (Tor) excels in providing access to hidden services and is user-friendly, while I2P offers better resistance to censorship and is more focused on internal network privacy. Both prioritize anonymity but cater to different user needs and experiences.