__author__

[David Keeney]

I see this set (or similar) of variables in various modules I read. 
They are found near the top of each module file, outside of any class
or function definitions.

"
__author__ = "Software Authors Name"
__copyright__ = "Copyright (C) 2004 Author Name"
__license__ = "Public Domain"
__version__ = "1.0"
"

What is the function of this set of variables?  I assume there are
software products that use these, (Python itself, perhaps), that
expect to find certain variables explained.

What are the expected variables, other than the ones listed above, and
what software would I expect to use them?

David