I2P Firefox Browser Profile
An eepsite is a website that is hosted anonymously, a hidden service which is accessible through your web browser. It can be accessed by setting your web browser's HTTP proxy to use the I2P web proxy, port 4444, and browsing to the site.
To make that easy, the Firefox browser profile is pre-configured to work with I2P. While you can use any browser to access I2P sites, using a dedicated browser profile keeps your I2P browsing activity separate from your clearnet activity.