The art of Copy and Change is rule number one on Open Source
So yes, the main idea behind Open Source is that, many projects will be developed, based on some software/code that was already developed by other people. For example, on Linux we see what most try to do as something different is in fact some copy of the original source, personalized and given a different name. Ubuntu is developed based on Debian and inside the Debian world, you have many similar distros, where it's core, is equal to all others. In that perspective, only few distros try to change the core features adding new ones or removing from the original source.
The same happen with BSD after having some Public Open Source code repositories to explore it, by reading the code, writting new one and by that condition, modify the code. The same happen to Music Bands, from groups or solo ones. They all get inspiration in some other Music projects. Even if the sequence of Music Notes is almost infinite, is easy to find similar or equal sequences listening Music. But we have Computers, Cards, Cars, Bikes, Planes, AI services, Food, Cultures, etc. All pass throught this copy and modify cycle of life to make small changes "better", since we all learn to speak by the same condition: Repeat[Copy into Memory] and Write[Modify original source of learning], to create new paradigmas, new stories, new lessons, new objects, new concepts, etc.
Is the Common aspect Between All of Us.
With this normalization in mind, let us add some "new" BSD alternatives that are not refered in the above BSD link: With the last update 1 year ago, MirBSD for the 32Bit architectures, Fuguita which is based on OpenBSD, PFSense that create a Web interface to manage Firewall and other toolings, like OPNSense variation do, the minimal MidnightBSD cat, the XigmaNAS dedicated system to help administrators work and like odicforcesounds domains, there is always some Dragon in this BSD story that is Awesome too.