I2P (means Invisible Internet Project, though it is not commonly referred to by this name anymore) is a mixed-license free and open source project building an anonymous network (or, more accurately, a pseudonymous overlay network).
27 January 2016 / July 31, 2015
|Operating system||Cross-platform, including: Microsoft Windows, Linux, macOS, OpenBSD, FreeBSD, Android|
|License||Many: BSD licenses, GNU General Public License, MIT license, released into the public domain by the copyright holder|
The network is a simple layer that applications can use to anonymously and securely send messages to each other. Possible uses include anonymous surfing, chatting, blogging and file transfers.