iTop data collectors are simple PHP command line applications to collect data from an external application and load/synchronize the information into iTop using the data synchronization mechanism built into iTop.
This module is the extra part to collect data from VSphere. It needs the collector base module to work.
For more information about this module have a look at the corresponding extension documentation.
Release packages can be found on the iTop Hub Store. This is the best way to get a running package as those contains all the needed modules and stable code.
When downloading directly from GitHub (by cloning or downloading as zip) you will get potentially unstable code, and you will miss additional modules.
This iTop module development is sponsored, led and supported by Combodo.