"Copyright can be applied to software to limit how it may be
copied and distributed. As I examined in my last article, Open
Source Software and the Myth of Viral Licensing, copyright alone is
not enough to define what a software purchaser may do. Thus, in
addition to being copyrighted, virtually all software is
distributed under the terms of some license that spells out what
the user is and is not permitted to do with the code.
"Proprietary commercial licenses, like those under which
Microsoft and Oracle offer their packages, generally forbid
customers from examining the source code or even decompiling
executable files; users may not make copies or otherwise share the
software with others; finally, users are not permitted to
distribute any modifications to the licensed software..."
