How does including MIT Licensed code in an EE Addon work?

Question

Things I'd like to admit and apologize for in advance:

• I am very new to StackExchange and have a feeling this may be too subjective, but I'm not sure.
• My understanding of the different types of software licenses is poor at best.

So here is my actual question. I am considering using a jQuery plugin in one of my commercial ExpressionEngine Addons. I know that the MIT license allows me to sell my addon, so long as I include a copy of the MIT license. Does it matter WHERE in my addon this license is kept? What would happen if down the road I needed to include another piece of code also released under the MIT license? Do I then need to include two copies of the license?

Is there a standard convention as to where these licenses should be stored within an EE addon?

I understand in advance if this needs to get closed for being off-topic, or too subjective. But figured I'd give it a shot. What are my other options? The EE forums? :)

MW

Answer 1

So given the proportion of EE addons that are sold commercially I think this is a relevant question, I also don't think this is a subjective question because the MIT license is actually pretty clear. The relevant section being:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

"The software" being the MIT licensed code rather than your addon. Therefore if you include multiple pieces of MIT licensed code, include a copy of the license with each of them. If it's a single file like a jQuery plugin the easiest thing is to put the license at the top of that file (where it probably already is). If it's a library that spans multiple files include the license in the location in which it is provided and reference it from your (distributed) documentation.

NB if you're really worried about this stuff do consult an actual lawyer rather than taking the word of some guy from the internet. That said, the MIT license was designed to be both easy to read and explicitly non-prohibitive to including MIT licensed code in commercial software. To be well covered I suggest you:

• Leave a full copy of the license at the top of the jQuery plugin file that you distribute with your addon.
• Also include a reference to your README file to the fact that the addon uses said plugin/libraries and that these elements are MIT licensed, and the license is included in the relevant files.

In general developers use the MIT license because of it's permissive nature (vs something like the GPL), so if you do make an error the worst that is likely to happen is that the plugin's author asks you to amend it.

There are a large number of similar questions on Stack Overflow on this topic (eg this one so that would be a good place to conduct further research if you feel the need to gain more clarity.