free and open source project building an anonymous network

I2P (means Invisible Internet Project,[3] 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).

I2P logo.svg
Developer(s)I2P Team[1]
Initial release2003; 19 years ago (2003)
Stable release
27 January 2016; 6 years ago (2016-01-27)[2] / July 31, 2015 (2015-07-31)
Written inJava
Operating systemCross-platform, including: Microsoft Windows, Linux, macOS, OpenBSD, FreeBSD, Android
TypeOverlay network
LicenseMany: 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.


  1. "I2P Project Members". geti2p.net. Retrieved 2015-11-22.
  2. zzz (27 January 2016). "0.9.24 Release". geti2p.net.
  3. IRC Meeting #59: <jrand0m> i2p = i^2p (invisible internet project)