References to the Lua license, was Re: Copyright question

[marbux <marbux@...>]

> Well, Lua is licensed under MIT/X11
> in order to give people freedoms
> regarding their licensing choices,
> including licensing under the GPL.

There is a widespread misconception that Lua is licensed under the
MIT/X11 license. It is not, although the differences are immaterial in
almost every imaginable circumstance.

Since version 5.0, Lua has been released under the Expat variant [1]
of the MIT license. Compare the Lua license for 5.0 and later [2] with
the Wikipedia discussion of differences between the two MIT license
variants. [3] . The Lua license does not include the last two
paragraphs of the MIT/X11 license,  [4]  which is what differentiates
the Expat and X11 variants.

When the intent is to license under the same terms as the Lua license,
to avoid ambiguity and confusion should a legal confrontation occur, I
suggest identifying it as identified on its web page, "License for Lua
5.0 and later versions" and linking that license, rather than
referring to and linking one of the MIT licenses.

Alternatively, you might refer to it as the "MIT/Expat License." But
"MIT/X11" does not match the current Lua license and "MIT License" is
ambiguous, encompassing at least two variants.

Best regards,

Paul

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[1] Expat license: http://www.jclark.com/xml/copying.txt (note that
James Clark originally created the Expat license by pruning the last
two paragraphs from the X11 license)

[2] Lua license: http://www.lua.org/license.html#5

[3] Wikipedia article: http://tinyurl.com/3qbzwjw

[4] MIT/X11 license: http://tinyurl.com/3t9zffk