"Capitalism is a social system based on the recognition of individual rights, including property rights, in which all property is privately owned."

Ayn Rand believed that there is no such thing as "public property". What is commonly referred to as such is the private property of a government. She would probably have had no use for "public domain" software. This is uncopyrighted software and has no owner. In contrast, Open Source software, including all of GPL-ed software, is copyrighted by its authors, and hence is not "public domain" but clearly privately owned. Not only that, since the software is owned by none other than its creators, Rand would have had no argument at all with the property ownership aspect of Open Source.

The Rights of the Producer

"The right to dispose of one's income belongs to the producer, and if he wishes to give it to an heir, a charity, or to flush it down the toilet-that is the producer's right. It is not any of your concern, and it certainly is not the concern of the government."

Rand clearly believed that the producer of wealth alone had the right to determine what to do with it, and stated this in no uncertain terms. When we say today that the author of a piece of software gets to choose the license under which to release it, we are echoing Rand.

A programmer may release his or her work under a commercial license or an Open Source one such as the BSD license or the GPL. He may even choose not to copyright it, and put it into the public domain instead. We may all have our individual preferences for one course or another, but as Rand admonishes, the producer alone has the right to decide how to dispose off his creation. Therefore, she would have had nothing to say against programmers choosing to release their software under the GPL, of their own free will.

Trade

"Free competition is the freedom to produce, and the freedom to trade what one has produced, for one's own self-interest, i.e, in the pursuit of one's own happiness."

Rand also wrote that under Capitalism, one might obtain property from another in only one way-by their voluntary consent. Rand said that by banning the initiation of physical force, Capitalism leaves only one way for people to deal with each other-through trade, which Rand called "the highest form of voluntary social cooperation."

Rand was implacable in her opposition to the use of force for any purpose but self-defense. She believed that Capitalism is based on individual rights, free will and free choice, not force or fraud.