When submitting a package to the Concrete CMS marketplace and it includes 3rd party code, here are some notes on licenses. I had some help from an AI generating these summaries. These are summaries, not legal documents, so check the original and don't trust me!

General

• Licence: You must include a copy of all 3rd party licenses with the addon or theme.
• Give Credit: Usually optional, be nice to the 3rd party developer and give them credit (such as a link).

MIT, BSD, Apache

• Commercial Use: You can sell it onwards, no restrictions. No onward license restrictions. The 3rd party components retain their original license.

SIL Open Font License (OFL)

• Commercial Use: Free, can be sold on as part of a product, but must not be sold by itself.
• Derivative Fonts: Must not use the name of the original font.

GPLv3

• Commercial Use: You can sell code that incorporates GPLv3 components, but you must also make it freely available.
• Source Code Availability: You must make the entire source freely available, including your own code and any modifications you’ve made to the 3rd party code.
• License Consistency: Your code must also be licensed under GPLv3, ensuring that the same freedoms apply to anyone who uses or distributes it.
• Freedom to Modify and Redistribute: Recipients of your software have the right to modify and redistribute it under the same GPLv3 license. This means they can share it for free or even sell it themselves.

LGPL

• Dynamic linking: If you don't distribute the LGPL item with your package, then you can dodge the GPL requirements. For example, you pull in the 3rd party asset from a CDN without modification.
• Freedom to modify: Users of your package must be able to replace the LGPL component with whatever they like. 
• Commercial use: As long as you comply with the above, your code can be sold commercially without making it open source.

GSAP (GreenSock Animation Platform)

• Free for most free uses: As the end product is not something that directly competes with GreenSock and is not sold.
• Commercial Use: If your code is part of a product you sell you need a commercial license from GreenSock.

Since April 2025, Webflow has made GSAP free for all uses.

BSL (Business Software Licence)

• Commercial Use: Commercial use is prohibited without explicit approval or a commercial license from the licensor.
• Transition to Open Source: After 4 years the software moves to an open-source license such as GPLv3.
• Change Date The 4-year period applies to each specific version release of the software.

Creative Commons

There are many levels of CC licenses, ranging from as open as GPL and as freely commercial as MIT.