In my opinion, there are two big things that Kernel brings to the table: 1) Arguments are not automatically evaluated before being passed to the underlying "op

In my opinion, there are two big things that Kernel brings to the table: 1) Arguments are not automatically evaluated before being passed to the underlying "operative" in Kernel-speak. This is important because it obviates the need for the macro machinery. This is fairly similar to Tcl. 2) Environments are first-class in Kernel. This is important because you can now constrain the scope explicitly. Do I want to evaluate this in the defining context (lexical scope)? Do I want to evaluate this in the calling context (dynamic scope)? Do I want to evaluate this is global or initial scope? All of these things are possible because environments are a thing that can be passed around. The downside is that this level of mutability seems to constrain the ability to pre-compile things. One of the "problems" that I would consider Tcl to have is that certain "atoms" don't self-evaluate. There's really no good reason for why you have to write: % if 1 {expr 2} else {expr 3} instead of % if 1 2 else 3 And no good reason why you can't write: % + 1 2 3 instead of % expr 1 + 2 3 This seems like going gratuitously out of the way to avoid "looking like Lisp" which was in its down phase by 1990.