Once the core ACT tools have been installed, this is the next package that should be installed.
This package contains a number of standard definitions for data types, channels, global variables, and basic functions
that will be installed in $ACT_HOME/act. This path is part of the default search path for any ACT tool.
The comments in the .act files have some basic documentation.
Set $ACT_HOME to the root of your ACT installation, and then run make install