I am very much a GPL advocate, and the more I get into programming the more I favour the GPL licenses. I have many reasons for this, some of them applying to myself personally, but others that are applicable at a larger scale as to how it benefits software creation in general. However, I will start out with how I came to use Free Software and why I ended up with the mentality towards software licenses I have today.

For 15 years all I really used were Mac computers, which are Unix based systems but still proprietary. It's not practical to imagine I would know or care about something like licensing or ethics during this time, I don't believe I arrived at the age of reason until I was around 15, and although some of my personality and beliefs have changed since then, my thoughts have not strayed much from what they were at that age. When I was 15 I got my first personal laptop that I could use for my own purposes. It was an old laptop that my dad used to use for work, but for work he always used GNU/Linux, and the laptop did not have Windows, and even if it did it was an old 32-bit computer with 1GB of RAM (I ended up adding another GigaByte to that). Even if I wanted to use Windows on there I couldn't because it wouldn't run as quickly as GNU/Linux. So this was the first time I ran GNU/Linux as a main OS. At this point I didn't care too much about Free Software, but I was well on my way to being a Free Software advocate, as my political ideology had moved very much left-ward where Free Software can almost be considered the licenses of the left-wing.

After a few years of running GNU/Linux I started to get rid of all the Apple products I had (because Apple makes it hard to use their products with anything else that isn't theirs, mostly being the iPod I had which didn't like syncing with my GNU/Linux machine until I found a hack that got me to fix that). At one point I came to the conclusion that the reason why Apple products (along with others) did not play well with others is because they are non-free and do not allow people to create programs that work with their products (because that means you're using someone else's stuff instead of their stuff). After this pissed me off I personally decided to stop using non-free software as much as I could to the point where now the only non-free software on my computer are some wireless drivers that I need for my laptop.

While I used GNU/Linux I also started to get into programming, which is where I was exposed to software licenses. Since I was on an old computer I couldn't really do much gaming, but I could do a lot of programming, so I ended up programming small games that I could play. But when the time came to choose a license I decided on the GPL, reason being (at the time) that I want people to be able to learn from my code, but I don't want people to take advantage of me by grabbing whatever code I create and making it proprietary and then improving upon it, as that would essentially be stealing my foundations and building on top of it without giving back. So I sided with the GPL licenses.

However, those are only personal reasons that I had at the time, there are more reasons that do not affect me personally but are important at a larger scale. This being that GPL promotes people to contribute and promotes collective improvement to a project instead of everyone making their own version of the wheel. If I create code that is useful and then share it someone else can use that code to make something that's even better and then someone else upon that continuously improving the software. Meanwhile, with other licenses such as MIT or BSD people can simply take your code and make whatever improvements they make proprietary forcing everyone else to have to reinvent that wheel. Of course, attribution license defendants will say that many times these entities do return code to its original source, and although that is true, I would rather not rely on the good will of a few nice people, but rather force everyone to share what they have in order to assure that progress can be fluid and continuous.

I believe that the GPL licenses create a more educational environment and that they allow for more progress following the scientific philosophy of building upon the shoulders of giants. With that mentality I believe we can get much further than what could be created with each of us going our own separate ways without having any knowledge of what the other has done.