FreeBSD is Free
FreeBSD is free—free as in speech as well as free as in beer.
Here's a quick rundown of what "free" can mean and how "free" various OSes are:
- Microsoft Windows costs $$$ and you may not do anything with it except run it under very narrow conditions licensed to you by Microsoft. You not only may not see the source code to enhance it for your own or others' benefit; you may not even reverse-engineer it to try to figure out how it works for yourself.
- Generic GNU/Linux does not cost $$$. You may redistribute it as you see fit. You not only may, but must be allowed to see the source code to aid you in either auditing or altering it as you see fit. You must, however, make any alterations which you make to its source code also available under all of these same terms—you may not make them proprietary.
- Some specific variants of GNU/Linux, such as some versions of Red Hat Linux are "free" in the sense that anyone may download the source code and audit/evaluate/alter it as they wish under the terms of the GPL as outlined briefly above, but are very distincly NOT free in the "free beer" sense—or in some cases of the "free speech" sense—in that crucial portions of the base functionality of the operating system are not unlocked unless you pay the maintainers for a set of services, and authenticate yourself to them to prove who you are and that you have so paid. As an example, you cannot use the "up2date" utility (which keeps your installed binaries current with the distribution's current versions) under certain versions of Red Hat (namely their Enterprise series) unless you have a subscription and authenticate yourself with a certificate.
- FreeBSD does not cost $$$. It may be redistributed as you see fit. You not only may, but must be allowed to see the source code to aid you in either auditing or altering it as you see fit. But where the BSD license differs from the GPL license is this: You may use portions of the BSD code for proprietary purposes, and aside from crediting your sources, you are NOT required to make portions of the code you reuse or your own alterations available under the BSD license or any other license. In addition, no part of the operating system is designed to be usable only if you maintain some sort of "subscription" to any organization; for example the ports and packages systems, which are roughly analogous to RedHat Enterprise's up2date system, are available to anyone and everyone without need for SSL certificate identification.
GPL "free," or BSD "free?"
One of the biggest starting points for BSD-vs.-Linux holy wars is the issue of which is better, the BSD license or the GPL license. In fact, each have their strong points and their weak points. The GPL not only encourages but forces free licensing of software, which many authors feel ensures that their work will remain free and will not have its focus stolen by commercial and proprietary efforts using their codebase. The BSD license, however, encourages the developers of commercial and proprietary products to adhere to open standards by providing them with a codebase which they can review and re-use as they see fit without being hampered with restrictive licensing which could harm or destroy their profitability as commercial developers. Without BSD's considerably less restrictive licensing scheme, we might very well not all be using the TCP/IP protocol on an open Internet today: virtually every operating system on the planet used BSD's original TCP stack when adopting that protocol, and a surprising number of them, both commercial and free, still have snippets here and there even today.