unpack http://i3.cs.berkeley.edu/download/i3_0_3.tar.gz in the top directory (hipl--main--2.6)
make sure that the link "hipl--main--2.6/i3" points to the unpacked i3_0.3/i3 directory
Compile hipl--main--2.6 with ./configure --enable-hi3
Not tested for a long time. To work, needs to use some set of i3 servers started locally from i3 distro or running on PlanetLab. See e.g. http://hipl.infrahip.net/i3_status.html or http://rose.cs.berkeley.edu:8080/i3_status.html