Kaleidos CEO here (Taiga+Penpot). It's not free at all but we want to make sure we have an honest and sustainable business model. We made stupid mistakes with Taiga a few years ago (a bad mix between an open source product and a proprietary SaaS style pricing. We have enough resources to make sure we can build great tools first without being obsessed about charging but Taiga would be straightforward. Penpot is different, though, because it is the first design&prototype tool that's open source and we are not sure what business model would make sense. Open Core focusing on great self-hosted and SaaS options plus Tax-the-rich for premium features doesn't sound too bad but, yet still, we are not entirely sure. For the time being this is not a pressing matter but the team and resources that Taiga and Penpot require are not trivial. I mean, look at the challenges that Penpot is addressing... no wonder there are only a handful of tools like this, they are extremely challenging to build. Furthermore, we want to make sure Penpot is the designers' tool of choice also for devs once they get to respect the design process.