Why closed source?

[Kuci]

hashcat does not need to be open source.

If you feel it this way, I cannot argue with you. But at least if you could make some kernel interface, with which we could be able to create our own kernels with algorithm we would like to use, that would be great. I think this is the only thing that most of users would be interested in if hashcat was open-source, but making such a SDK would be more than enough and it would be really appreciated.