EZtorrent should build on most POSIX systems. EZtorrent will not work on Windows. BitTorrent should already be installed before building EZtorrent, so that EZtorrent's configure script can find BitTorrent's commands, which should be located in the search PATH.
This version of EZtorrent was tested with BitTorrent 4.0.2. It's possible that a new version of BitTorrent will introduce new or incompatible option to the various BitTorrent scripts. When upgrading to a new version of BitTorrent make sure to verify that all BitTorrent commands are still compatible. EZtorrent logs all BitTorrent commands it runs during its ordinary course of business to syslog, and they can be cross-checked against BitTorrent's documentation.