A license is a set of statements or a document that sets the terms on how a work may be used, permitting some uses of the work, and denying or restricting others. The license of the work is granted from the work's owner (the author or the publisher) to the work's user.
Licenses are legal agreements. If the user breaks the terms of the license, often this means that the license is terminated, and the user no longer has permission to use the work in any way. A user who ignores the terms of a license might also be sued by the owner.
Permissions and restrictions
For example, a license may grant, restrict, or deny the right to:
- run or execute the work (that is, play the game),
- make a backup copy of the work,
- have copies of the work on multiple machines,
- make a copy of the work for someone else,
- upload the work to an archive or similar repository,
- offer the work for on-line play,
- distribute the work with or without full attributions and associated files,
- edit or patch the work,
- make a derivative version of the work,
- sell copies of the work.
If you want to do something which a work's license does not allow, you should consider asking the author directly, as they can always grant specific permissions on a one-off basis.
Types of licenses
Freeware simply means that a work is distributed to users without them needing to pay a fee. IF works distributed without explicit licenses are usually assumed to be freeware. If no explicit license is stated, then it is best to assume that the author desires to keep all their rights, and that, for example, you cannot sell it (even for just for the cost of the CD itself), redistribute it, or create a derivate work.
Shareware is a type of license where the user is initially granted the use of the software without charge, but later expected to make a payment.
Creative Commons refers to a set of licenses for creative works that voluntarily give up many of the rights given by copyright law. Because of their popularity their terms are widely understood, and so are good choices for those authors who do not want to retain the maximum control over their works given to them by copyright law.
Free and open source software
Free and open source software (FOSS) refers to a movement committed to software that is both flexibly licensed and distributed with its source code. "Free" in this context does not refer to price, but the freedom to use and change the software. There are many FOSS licenses, and they can be used to license IF. However as IFs are also creative works, not all FOSS licenses are appropriate and licenses specifically written for creative works (like the Creative Commons licenses) may be more appropriate.