This pages discusses software licenses in general.
If you are a software author, you should think carefully about what kind of end-user license agreement (or EULA in legal parlance) you use. You might consider what category your work falls under and how you want people to use it:
See also Open Source.
For the purposes of this information, "extension" refers to any script written in the Tcl language, and also programs that employ the Tcl C API.
The Tcl/Tk license imposes no restrictions on the author of a Tcl extension as to copyright ownership of the extension, or as to how the extension may be licensed.
The TCT encourages extension authors to use a BSD-related license similar to the one used in Tcl/Tk/tcllib/tklib/etc. as some companies find it less restrictive than the GPL or LGPL.
Whenever you begin hacking on someone else's code, it is always good to know the term under which that code is licensed, and what the implications are for your modifications.
escargo 2005-05-24: Licenses, like many other kinds of policies, are usually reactions to some kind of problem. I think it might be useful to try to determine what problems different licenses are trying to solve, and then compare the different problems. (For example, I would say the Gnu Public License is trying to solve the problem of people using code to create products from available code without making the changes available.)
Lars H: Could anyone natively-English-speaking comment on the two spellings "licence" and "license"? Looking in a printed dictionary (these tend to be more reliable than the net in such matters) I find "licence" listed primarily as a noun, whereas "license" is only listed as a verb. Yet I see both used as nouns all over!
WordNet (r) 2.0 licence
noun 1: excessive freedom; lack of due restraint; "when liberty becomes license dictatorship is near"- Will Durant; "the intolerable license with which the newspapers break...the rules of decorum"- Edmund Burke [syn: license]
2: freedom to deviate deliberately from normally applicable rules or practices (especially in behavior or speech) [syn: license]
3: a legal document giving official permission to do something [syn: license, permit]
verb 1: authorize officially; "I am licensed to practice law in this state" [syn: license, certify] [ant: decertify]
LV: Well, I speak American English, and people I know here are frequently poor spellers, and likely to spell the word which ever way seems to come out of their fingers at the moment.
I don't recall during any schooling any discussion or argument regarding the use of one spelling versus the other.
Perhaps our British readers might chime in here from their perspective.
MG: According to my OED, in en_uk licence is a noun and license can be a verb or a noun. It also says that in en_us, license can be either a verb or a noun, and licence is just a verb. I tend to just use 'license' for everything, myself...
RS ponders that for the noun, both forms derive from Latin licentia...
MJL: In (British) English, licence is the noun and license is the verb. The suffixes are the same in the pair practice/practise. My understanding is that in American English there is only one spelling - license (also practice) - for both noun and verb.