I really appreciate the design principles behind Cuis. Great to see it mentioned here.
I'm sure there must be plenty of people (like me) who have heard good things about Smalltalk over the years but haven't had much chance to explore it. If you want to dip your toes in the water, and if you agree with the following quote from Cuis's lead developer (Juan Vuletich), Cuis is definitely worth a look.
"Unbound complexity growth, together with development strategies focused only in the short term, are the worst long term enemies of all software systems. As systems grow older, they usually become more complex. New features are added as layers on top of whatever is below, sometimes without really understanding it, and almost always without modifying it. Complexity and size grow without control. Evolution slows down. Understanding the system becomes harder every day. Bugs are harder to fix. Codebases become huge for no clear reason. At some point, the system can’t evolve anymore and becomes “legacy code”.
Complexity puts a limit to the level of understanding of the system a person might reach, and therefore limits the things that can be done with it. Dan Ingalls says all this in “Design Principles Behind Smalltalk”. Even if you have already done so, please go and read it again!" [0]
In terms of documentation, several free books on Pharo are available at https://books.pharo.org/
As it's development is fast paced, they tend to get a bit outdated fast. But at least the basic ones get updated often. Most recent versions are from 2022. I think the framework you are referring to is Zinc.