Tikhon Jelvis, Lead Data Scientist at Target (2016-present) has a very good answer to "Is free software socialism?" at https://www.quora.com/Is-the-open-source-movement-socialism - I will quote the answer in its entirety for the benefit of this thread...

No. The two are not related in any useful or meaningful ways.

The first thing to note is that there are actually two core ways of thinking about open source software: the "open source" movement and the "free software" movement. While the two work together perfectly well—and most people probably share some of the views from both camps—they are philosophically distinct.

The open source movement is pragmatic at heart: the main idea is that developing software in the open leads to better software. More eyes and more diverse opinions on your codebase is a strength that often overshadows the commercial benefits of keeping software proprietary. This is the camp more often associated with more "permissive" licenses like MIT and BSD, and mirrors the philosophy I've seen at most companies that release and maintain significant open source projects (often based on their own internal tools).

This movement has no parallels to socialism whatsoever. It believes in open source collaboration as a strong model for software development but doesn't opine at all about property rights.

The free software movement, spearheaded by the Free Software Foundation (FSF) and Richard Stallman, is more ideological at heart. It originally started from the idea that you, as a consumer, have the right to understand and modify the software that runs on your machines. This is codified in the four freedoms that Free Software aims to protect:

* The freedom to run the program as you wish, for any purpose (freedom 0).
* The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.
* The freedom to redistribute copies so you can help your neighbor (freedom 2).
* The freedom to distribute copies of your modified versions to others (freedom 3). By doing this you can give the whole community a chance to benefit from your changes. Access to the source code is a precondition for this.

These freedoms are often enacted with "copyleft" licenses like the GNU Public License (GPL). The idea is that you have the right to read, modify and distribute software under the GPL (including selling it commercially) as long as you distribute it under the same license. You can do more or less whatever you like as long as you provide all your users with the modified source to your software and give them the same rights.

The motivation behind the movement is to protect the rights that you have over your own devices and software, which is not significantly related to socialism at all. If anything, it's a way to strengthen what you can do with your own property!

There is one way you could see the Free Software movement in a way that parallels socialism: it's a collective effort and stands against "intellectual property".

However, this view misses some important details. Unlike socialism, Free Software is not concerned with property and how it is distributed in society; rather, it simply does not view "intellectual property" as property at all. In fact, many people in the movement don't regard "intellectual property" as property at all; instead, they view the term as a misleading way to group together several fundamentally unrelated laws into a single concept.

Richard Stallman wrote an interesting essay on this topic: Did You Say “Intellectual Property”? It's a Seductive Mirage. His style is not for everyone—he comes off as very certain, almost fanatical, about his views—but it makes the idea eminently clear. The core idea is that copyrights, patents and trademarks are all fundamentally different from each other and fundamentally different from physical property; the term "intellectual property" is misleading because it groups these three disparate concerns together and implies they are variants on physical property.

There is nothing socialist about that view whatsoever. Trying to reform the laws and cultural norms around "intellectual property"—especially when you realize it's fundamentally distinct from other notions of property—is entirely orthogonal to socialism.

Both the Open Source and the Free Software movements are fundamentally unrelated to socialism.