Licensing

A license is the set of restrictions on what you can do with a game.

Source code and binaries (compiled executables) may have different licenses. A source code license restricts the use and availability of code, the binary license restrictes the use and availability of the game. To play a game, you usually only need to be concerned with the binary license. However, if the game is not available on your platform, or you have political objections to closed sourced proprietary software, the code license can also become important.

Usually, if the source code is available, the game is freeware. However, some games may license the art assets separately from the code. Thus, the code may have no cost, but the art assets may require a purchase. The "game license" is taken to be the most restrictive of these licenses.

This is not a legal definition. Many other sites go into exhaustive depths as to the nuances of these different licenses.

Source licensing

Closed source

The source code is not available to the public. Only pre-compiled binaries are available. This makes the program very difficult to extend or modify. This is usually enforced by a EULA (End User License Agreement), which forbids the reverse-engineering of the executables.

Source code available

The source code is available but you are not allowed to reuse it, even if you release your derived works. Rarely used, since not being allowed to make modifications defeats the sense of releasing the source code.

Open source

There are two major types of open-source licenses:

• Permissive licenses, such as the BSD license, allow including the code in a work released under a different license, which can be more restrictive.
• Copyleft licenses, such as the GPL, have provisions that require all derivative works to be released under the same license.

Public domain

Some authors are willing to release their work into the public domain, which means that no restrictions apply in any case. Very old works (usually 70 years after the death of their author) automatically lose all restrictions.

Game licensing

Commercial (proprietary)

You must purchase the game before you can play it, and must not share the game with others. Many commercial games provide demos, which conflates Commercial with Shareware. Often the (arguably poor) distinction is made that Commercial has a box in a store shelf, while Shareware is internet only. Almost always closed-source.

Crippleware and demos

You can download and play the game without paying the original author; however, the game is limited in some way. For example, you can only play it for a certain length of time, or only part of the game is available, or some features are missing. To play the full game, you must purchase it. You are usually free to share the shareware version of the game with friends, but CD compilations are sometimes frowned upon. It is suggested that you contact the author before you redistribute in a large scale. Crippleware is often called shareware, because that sounds nicer.

Shareware

You can download and play the game without paying the original author; however, you are morally obligated to pay the author if you like it enough to keep playing. Sharing and redistributing the game are encouraged.

Freeware

You can download and play the game without paying the original author. There is no limited time period to play the game and the entire game is available to you. While you can freely give the game to your friends, many freeware authors frown on CD compilations. It is suggested you contact the author if you wish to redistribute in a large scale.

Postcardware and emailware

Freeware license terms apply. If you would like to thank the author for creating and maintaining a game you are encouraged to send him/her a postcard. Emailware is the more modern variant, which asks for the said email to be sent to the author.