• Read the code
• Modify the code
• Redistribute your changes to the code under the same rights they were given and shall not limit the amount of money they must charge for the code
• Use the software regardless of race, creed, culture, or geographic location
• Use the code for whatever purpose the user desires
• Separate parts of the code from the package it is distributed under (eg. pull the TCP/IP stack from FreeBSD)
• Distribute the software in whatever manner they wish (eg. not forcing the software to be distributed on CD-ROMs)
• Distribute any other software the user wants with the code

The Licenses

• Gnu Public License (GPL): The GPL is the iconic Free Software License. It cleverly uses copyright law to force people linking to or extending any GPL'ed software to release their software under the GPL. It is commonly referred to as a "viral" license. There are many misconceptions about this license and its relationship to business. GNU/Linux, Emacs, and OpenACS are all examples of GPL'ed software.
• Lesser Gnu Public License (LGPL): The LGPL is a slightly less restrictive version of the GPL allowing people who merely link to LGPL'ed code to use whatever license they want. LGPL used to be called the Library GPL and was used for things like the Gnu C Library.
• BSD Copyright License: This license is one of the least Open Source licenses. It allows the user to pretty much do whatever they want with the source so long as they include the disclaimer and a small notice that this was once a BSD product. Most of the BSD's (FreeBSD, OpenBSD, and NetBSD) use licenses similar to this one./li>
• Apache Software License: This license used by all the Apache software is very similar to the BSD license. It has 2 additional stipulations: 1) that the name Apache not appear in the products name (without the Apache Foundation's permission) and 2) that the names Apache or Apache Software Foundation not be used to endorse the software (again without written permission). This means no "Powered by Apache" logo without permission. Apache Webserver, ANT, and Tomcat are all examples of ASL'ed software.
• Mozilla Public License (MPL): The MPL is in some ways similar to the GPL, but much less restrictive. The MPL requires that all modifications (if the product is released) either be included in the distribution of the product, or be available for download under ther terms of the MPL for a period of 1 year or 6 months depending on the situation. It also discusses Intellectual Property conflicts and states that anyone modifying the code should include information on any IP conflicts their modifications may have created. This is a relatively long license with additional rules about releasing modified versions of the license. An annotated version of the license is available for review. Mozilla browser and mail client are examples of MPL'ed software.

• Gnu Public License (Unofficial Translation)
• Lesser Gnu Public License (Unofficial Translation)
• BSD Copyright License
• Apache Software License
• Mozilla Public License

• Free Software Foundations review of Open Source Licenses