To the Free Software Foundation, the cost of software is irrelevant. When they selected the term free software, freedom, not money, was primarily on their minds. The fact that English uses the same word to represent both liberty and lack of cost was one of the reasons for the creation of the open source movement. To avoid confusion, we’ll adopt the Free Software Foundation’s convention of using gratis and libre to refer to cost and freedom, respectively.
To an outsider, the free software movement and the open source movement may resemble the "Judean Peoples’ Front" and the "Peoples’ Front of Judea" (from the film Life of Brian). The movements are remarkably similar in ideology, and most software that is open source is also free software. The main difference is the level of pragmatism in each camp:
- The free software community believes that non-libre software is antisocial—that a set of basic freedoms should accompany any software license, and not including them harms the user’s basic rights. To this end, they created the GNU General Public License (GPL). If you use code released under the GPL as a basis for a larger work, the result must also be licensed under the GPL. This concept is known as copyleft.
- The open source community believes that the development model pioneered by the increased collaboration generated by software-libre is superior to the closed development model. To this end, leading members of the open source community have been known to advocate a BSD-style license. The BSD license imposes fewer restrictions than the GPL—it prevents you from claiming credit for someone else’s work, but very little else. A company is free to take BSD-licensed code and release a closed-source product based on it. To a free software advocate, this plan is unacceptable; the creation of closed-source software is antisocial and so should not be condoned or encouraged. To the open source community, on the other hand, the original code is still available, and products based on it will eventually be superior to the closed version, so in the long term it makes little difference.
The ideology of the free software movement can be nice to watch from a distance, but from a business perspective it’s of little relevance. What is important is how these freedoms, or lack thereof, affect the bottom line. The side-effect of software-libre—the fact that it’s also usually gratis—can also affect this.
It is possible to "get the facts" from Microsoft and discover that the total cost of ownership (TCO) of a Windows system is lower than that of a similar Linux system. Microsoft, as the seller of Windows and the largest developer of off-the-shelf closed-source software, can be relied on to be completely objective on the matter of software-libre.
One of the major reasons Microsoft gives for the lower cost of Windows is the lower support costs. In general, it’s cheaper to employ someone for a task when a large number of people are able to fill the role. This is particularly true of support. For most support roles, individuals are recruited with a basic knowledge of the required software and gain experience on the job to fill more advanced positions. The basic entry requirement is access to the platform for home use—without this access, people getting onto the first tier are more expensive, and this cost percolates though the entire hierarchy.
Currently, only a lucky few potential recruits have never used Microsoft Windows. (Anyone who has never used Windows is lucky. The context here is computer support roles, not Windows support, and managing to avoid using Windows until the age when one would be applying for such a job is a case of extreme good fortune.) In contrast, fewer people have used Linux or Macs, and even fewer have used something like FreeBSD. The difference between Linux and Mac OS X here is that it’s possible for an unemployed system administrator to download and install Linux for free, and thus become more qualified for a junior Linux administration position. If more Linux-admin jobs are available, this option becomes more attractive. Thus, the inexpensiveness of Windows admins is a self-perpetuating cycle that isn’t necessarily stable long-term.
The difference is more obvious when comparing something less ubiquitous than an operating system. For a lot of small businesses, the software-libre database PostgreSQL is a viable alternative to Oracle. The starting salary for an Oracle administrator is higher, however, because very few people (legally) run Oracle as the back-end database for personal projects.