Copyleft: freedom and restrictions in free software

¶ … Copyleft is an interesting, fairly recent concept that modifies the traditional copyright procedure, offering more freedom from restrictions, but not totally free, like items in the public domain. Copyleft is a play on the word copyright, which protects products from reproduction or copying, but places many other restrictions on items, as well. Copyleft is usually used in connection with software, art, music, and documents.

Essentially, copyleft assures that a program or document will remain free throughout its history and modification. The editors of the GNU Web site, who originated the term, say, "Copyleft says that anyone who redistributes the software, with or without changes, must pass along the freedom to further copy and change it. Copyleft guarantees that every user has freedom" (Editors). Copyleft allows some distinct restrictions, but ultimately allows the software to remain free, even if it is modified or adapted by another developer, unlike proprietary software, which is always restricted in its use, but that also restricts free updating and modification.

Business managers who believe in free software embrace copyleft, because it allows others to develop and add to products and documents without charge, but that also does not allow them to charge for products if they use copyleft, which could decrease sales and profits for the company. It is important to understand the ins and outs of copyleft before employing it in a business setting.