So I was researching different distros, and I stumbled upon one called Poseidon (based on Ubuntu) which was intended primarily for scientific modeling. However, it hasn’t been active since 2018; also, after Poseidon 4, they shifted to focus primarily on oceanography.
So my question is, firstly, is there an active distro that has a similar intended purpose, and comes with all the relevant software? Barring that, is it easy enough to replicate just by downloading the relevant packages?
If the answer to both is no, my question is, how could one best go about resurrecting it as a fork? Would it be better to start from either Poseidon 9 (the latest) or Poseidon 4 (before they shifted direction), and then try to update all the core components? Or to start with the latest Ubuntu (or better yet Debian), and then simply install all the software needed to make it functionally identical to Poseidon?
Bonus question: if you start with an OS, and gradually replace one component at a time until all components have been replaced, is it still the same OS? (Theseus was a son of Poseidon, but unfortunately the name is already taken)
If you are ready to build your own packages and host your own repos, go for it. You should have some form of automation to at least get security updates, and it will take some recurring maintenance time no matter how you go about it. I haven’t looked closer at Poseidons repos but I think if this is a good idea or not depends a lot on the state of their build/packaging/distro code. It could be just a matter of cloning the repos, changing a few config parameters and running a couple of commands, or it could mean significant work, depending on how well it is engineered. You could start out and if you find yourself digging to deep in the process of getting a build, back out and reassess.
Kind of like others suggested, there are lighter options. All the big dists should have some form of build tooling to make kickstart/preseed/spins/whatever they call it where you can prepare a custom install ISO with your own set of packages. There are tools like packer and Nix that you can use either as part of building OS images or just script to run on a clean base installation of some dist. You can make an ansible playbook to automate setup and have that run by cloud-init. You could make a shell script to automate the installation of packages and setting up of environment.