-It isn’t protected by copyright law.

Example: Classic Literature

-Copyrighted work that you can copy, use, or give away for free.

Example: itunes, safari, internet explorer

-Copyrighted work that you can copy, share, and use for free, but only for a limited time, but if you want the full unlimited program you need to pay for it.

Example: apps in the app store

-Only allows the purchaser to use the software according the the licensing agreement.

Example: software you buy at the store

-A software with the idea that someone can improve the work.

Example: firefox and chrome