Ciro wasn't expecting it to be as old. Ported to C++ in 1992.
Besides the painful build, using FreeFem is relatively simple, as can be seen from the examples on the website.
They do use a domain-specific language on the examples, which appears to be the main/only interface, which is a bad thing, Ciro would rather have a Python API as the "main API", which is more the approach taken by the FEniCS Project, but so be it. This DSL business means that you always stumble upon basic stuff you want to do but can't, and then you have to think about how to share data between the simulation and the plotting. The plotting notably is super complex and they can't implement all of what people want, upstream examples often offload that to gnuplot. This is potentially a big advantage of FEniCS Project.
It nice though that they do have some graphics out of the box, as that allows to quickly debug common problems.
Uses variational formulation of a partial differential equation, which is not immediately obvious to beginners? The introduction https://doc.freefem.org/tutorials/poisson.html gives an ultra quick example, but your are mostly on your own with that.
On Ubuntu 20.04, the
freefemis a bit out-of-date (3.5.8, there isn't even a tag for that in the GitHub repo, and refs/tags/release_3_10 is from 2010!) and fails to run the examples from the website. It did work with the example package though, but the output does not have color, which makes me sad :-)
So let's just compile the latest v4.6 it from source, on Ubuntu 20.04:
Ciro's initial build experience was a bit painful, possibly because it was done on a relatively new Ubuntu 20.04 as of June 2020, but in the end it worked: https://github.com/FreeFem/FreeFem-sources/issues/141
The problem is that it compiling such a complex dependency opens up much more room for hard to solve compilation errors, and takes a lot more time.