Lua: open source or not?

[Nick Gammon <nick@...>]

From this page:

http://www.lua.org/about.html

"Lua is not an open-source project, with code contributed by several people: all code is written by us.".

From this page:

http://www.lua.org/license.html

"Lua is certified Open Source software."

Are the words "open source" being used in different ways here?

Assuming the license is indeed open source, the statement on the about.html page is a bit misleading.

- Nick