Comment by weinzierl

Pascal TeX to the best of my knowledge never did it but the web2c version does.

The description is a bit confusing because it can both dump only the warmed up interpreter image or the whole process, I think.

"With the program undump, you can use `core' to reconstitute a preloaded executable, which does not need to read a `.fmt' file to get started. Although preloaded executables save startup time, they have a big disadvantage: neither the disk space to store them nor their code segments (at runtime) can be shared. Therefore, if both tex and latex are running, twice as much memory will be consumed, to the general detriment of performance."

https://mirror.gutenberg-asso.fr/tex.loria.fr/texlive-htmldo...