The Freecell Solver’s Site Source Code
The Site’s Source Code
The sources of Freecell Solver’s site can be found here:
Main sources - as a subdirectory of the main fc-solve GitHub repository.
Site’s Assets - compressed archives/etc.
They are also under FOSS and open content licenses.
Note that building the site requires quite a few dependencies, so it may not be for the non-initiated. One can refer to the CI set-up for help.