[0 -Run
1 - (See, access source) Study
2 - redistribute copies
3 - redistribute YOUR MODIFIED copies]
"The Free Software Definition
The free software definition presents the criteria for whether a particular software program qualifies as free software. From time to time we revise this definition, to clarify it or to resolve questions about subtle issues. See the History section below for a list of changes that affect the definition of free software. "