megatron is part of Netatalk 2.x and was removed from newer versions due build issues. Don't know how it would have appeared on a macOS machine!
I've been tinkering with megatron recently actually. The main reason megatron doesn't work with modern netatalk is because AppleSingle support was removed from libatalk. I have a local branch where megatron is building again with netatalk 4.x but there are some bugs to work through.
If there is interest from the community, we can look into expanding the supported source formats.