Dependency

Java Runtime Version 7 or higher. (Oracle, OpenJDK, or IcedTea Java Version 7 or 8 recommended, except Raspberry Pi: OpenJDK 9 for ARM, PowerPC: IBM Java SE 7 or 8)
Determine your installed Java version here or type java -version at your command prompt. Java 9 support is in development and it is not recommended for general use.

Release Notes

Clean installs

Windows
9b20c38a392d5153759d2044ecdac7a90e79675738ead97bbcc731d972c47792

Download that file and run it.

Mac OS X
e5eb3db08dcc594e2fb01ada63303ff48096a454db1c7659c928ddb07736c84a

Download that file and double-click it (if that works) or type java -jar i2pinstall_0.9.43.jar in a terminal to run the installer. You may be able to right-click and select "Open with Java".

Command line (headless) install:

Download the 0.9.43 OSX graphical installer file above and run java -jar i2pinstall_0.9.43.jar -console from the command line.
Mac OS X Native (Beta)
cbda1767ef4156fc44168e87cd2475e6ba49792c11f6dcdf6fe76d2984cd0e00

A drag-and-drop installer that includes a new I2P Launcher utility. Beta.

Double-click on the file, then drag and drop the launcher into your Applications folder.

Linux / BSD / Solaris
e5eb3db08dcc594e2fb01ada63303ff48096a454db1c7659c928ddb07736c84a

Download that file and double-click it (if that works) or type java -jar i2pinstall_0.9.43.jar in a terminal to run the installer. On some platforms you may be able to right-click and select "Open with Java".

Command line (headless) install:

Download the graphical installer file above and run java -jar i2pinstall_0.9.43.jar -console from the command line.
Android
93e39b46001da498c9dad1ee94e5cb6301942a5dd2fe6b8405c7ccbed936d2bf
Requires Android 4.0 (Ice Cream Sandwich) or higher. If you earlier installed I2P, unfortunately this release fixes some IPC issues which will force you to uninstall your current installation before installing this. 512 MB RAM minimum; 1 GB recommended. The release and dev versions of the I2P APK are not compatible, as they are signed by zzz and meeh respectively. Uninstall one before installing the other.
Docker
35cb620d82c6cab8764792720c061379bb8493325d75ad2e376455b44718935

I2P is now available as a Docker package from the Docker hub. You may retrieve the image by running the 'docker pull' command.

docker pull meeh/i2p.i2p
    
Docker Hub
Source package
beb2a3c62efce826cd5aa3e296b483143ad2c581ddb038677f960f7d110df81c

Alternately, you can fetch the source from monotone or via Git from git.repo.i2p or Github.
Run (tar xjvf i2psource_0.9.43.tar.bz2 ; cd i2p-0.9.43 ; ant pkg) then either run the GUI installer or headless install as above.

Android source is in monotone and on Github. Android builds require the I2P source. See the documentation in the Android source for additional build requirements and instructions.

The files are signed by zzz, whose key is here. The Windows installer is signed by zlatinb, whose key is here. The Mac OS X native installer is signed by mikalv (meeh) with his Apple Developer ID certificate, whose key is here.

Post-install work

After running the installer on windows, simply click on the "Start I2P" button which will bring up the router console, which has further instructions.

On Unix-like systems, I2P can be started as a service using the "i2prouter" script, located in the directory you selected for I2P. Changing to that directory in a console and issuing "sh i2prouter status" should tell you the router's status. The arguments "start", "stop" and "restart" control the service. The router console can be accessed at its usual location. For users on OpenSolaris and other systems for which the wrapper (i2psvc) is not supported, start the router with "sh runplain.sh" instead.

When installing for the first time, please remember to adjust your NAT/firewall if you can, bearing in mind the Internet-facing ports I2P uses, described here among other ports. If you have successfully opened your port to inbound TCP, also enable inbound TCP on the configuration page.

Also, please review and adjust the bandwidth settings on the configuration page, as the default settings of 96 KBps down / 40 KBps up are fairly slow.

If you want to reach eepsites via your browser, have a look on the browser proxy setup page for an easy howto.

Updates from earlier releases:

Both automatic and manual upgrades are available for the release.

Automatic updates

If you are running 0.7.5 or later, your router should detect the new release. To upgrade simply click the 'Download Update' button on your router console when it appears.

Since 0.9.23, some releases are signed by str4d, whose signing key has been in the router since 0.9.9. Routers older than 0.9.9 will fail to verify update files signed by str4d, and will need to be manually updated using the process below.

Manual updates
d2749cca9a4ffe299a41660631d980fbe88d8f988a46808de0582a178d1ac9bf
  1. Download that file to your I2P installation directory and rename as i2pupdate.zip. (alternately, you can get the source as above and run "ant updater", then copy the resulting i2pupdate.zip to your I2P installation directory). You do NOT need to unzip that file.
  2. Click "Restart"
  3. Grab a cup of coffee and come back in 11 minutes
The file is signed by zzz, whose key is here.

Previous Releases

Previous releases are available on Google Code and Launchpad and within the I2P network on echelon.i2p.xyz.