"It started as a project at the university I was studying at. They just wanted a custom distro because... everybody was doing that at the time!" Pérez says.
"Since I'm very stubborn, the project kept going," Pérez adds.
The idea of software freedom – the kind of freedoms Richard Stallman laid out in the GNU Manifesto in 1985 and the original GPL in 1989 – are central to Trisquel. (In 2005, when Trisquel 1.0 was launched, GNU founder Stallman was part of the occasion.)
By software freedom "we mean the basic liberties the software user should have: those of using, studying, improving and sharing the software without limitations," Pérez says.
"It is a very important issue, because we now use computers for everything: our work, our leisure, our studies; and we should do it under our control. If the government uses software to manage data about the citizens, they should have the code to know for sure how the data is being treated and to guarantee privacy.
"If a school uses a computer for the kids to learn, they should be allowed to study how the tool is made and never get their teacher to answer 'you cannot know that'."
The distro was originally based on Debian's testing repository, but over the course of several years, Trisquel shifted to using Ubuntu as a base.
"The reason was to get a more predictable schedule to work on, and also because we felt that with Ubuntu gaining users it would be good to have a free drop-in replacement to it," Pérez says.
Trisquel strips out non-free software from Ubuntu and its package repositories. In addition to not recommending the installation of non-free software, other packages are modified to make them free. "[O]therwise-free software packages like Firefox needed to be modified to improve the user privacy and to stop them to recommend you to install non-free programs," Pérez says.
"Then both the Ubuntu and the Mozilla trademark forbid you to distribute copies of their software for a fee, which is against the free software principles, so we needed to rebrand the whole thing as well."
More easily visible changes are also made, including using a modified version of GNOME 3's Fallback desktop as the default desktop environment. This is partially because "GNOME Shell (the standard interface for that desktop) requires 3D acceleration to work, something many machines cannot achieve with free drivers, and partially to provide better accessibility," Pérez says.
Pérez rejects the idea that the distro is a 'just' an Ubuntu spin-off. He describes Trisquel's relationship to Ubuntu as akin to Ubuntu's relationship to its base distribution, Debian.
"What that means is that we have fully independent repositories and build servers, so we never redirect users to Ubuntu or other third-party services. We run everything ourselves, and we never add a package to the repo that wasn't compiled using Trisquel itself.
"That is very different from any other derivative you can think of, which are more or less customised Ubuntu live CDs."
"We keep adding packages to the list of the ones we modify and adapt, but we don't foresee [changing] the base or going fully independent," he adds.
"Partially because that would require a much larger scale project, and also because since over half of the GNU/Linux desktop users use Ubuntu and its freedom and privacy policies are not improving, we should have a free software alternative to it."
Pérez worries that despite the growth of Linux, the visibility of ideas about 'software freedom' have lost ground and been submerged of talk under the banner of 'open source'.
"In fact the Open Source Initiative was started with the sole purpose of providing a marketing wrapping to what the free software movement was producing so investors would not have to hear about the ethical problems that got the whole thing started," Pérez says.
"Many people are focused on practical benefits of free software like price or reusability, but avoid discussing deeper issues – that is why it is so usual to see non-free applications or drivers mixed within GNU/Linux distributions, because 'open source' just tells us that its software is better, not that the software that limits our freedom is bad."
"Despite what many GNU/Linux projects could lead you to believe, there are very few operating systems made solely of free software," Pérez adds.