[eigenspace]

I directed most of my comments towards CL because I know more about it than Dylan. My understanding is that Dylan lacks parametric types, so that comment can be straightforwardly applied to Dylan. IMO Parametric types are a really important part of this.

Regarding performance, I don't know much about this in Dylan. Was Dylan able to completely remove the runtime overhead of multiple dispatch for type stable code?

[pjmlp]

Yep, some research was done in that domain, https://opendylan.org/documentation/publications.html

Also note that it was competing against C++ as the Newton OS system programming language, it only lost due to politics.

https://news.ycombinator.com/item?id=15107367

[eigenspace]

Yes, I fully agree it's a darn shame that Dylan was abandoned by Apple.