What Are Freeware, Shareware, and Open Source Software?

Shareware is demonstration software that you use for a specific evaluation period (usually 30 days) without paying a fee. After the evaluation period expires, the shareware provider may require you to purchase a license for the software or to quit using it. Although it's virtually unenforceable, using shareware beyond the evaluation period violates copyright laws. Many companies develop their programs so the features and functions become disabled after 30 days — a polite reminder that the evaluation period has expired and you should pay for the program.

As the name suggests, freeware is software that's written and distributed freely over the Internet or on disks. There's no charge to use the software and no trial period. Typically, the author of the software maintains ownership and copyright of the freeware program and grants licenses for its use. A freeware license may, for example, bar users from modifying the software or attempting to sell it to others.

Open source software is software that's available in source code form for anyone to use. Although open source software doesn't have licensing restrictions that limit its use, modification, or redistribution, it usually has restrictions that preserve its open source status and control its development. Examples of open source software include the Linux operating system, the Perl scripting language, and the Apache Web server.