I remember discovering the Joy language (and combinatory logic) and being blown away by the elegance of being able to express programs just by composing functions. It was a pretty big epiphany to learn that when functions pop arguments from and push results onto a stack, the "application of a function to a data value" could be treated equivalently to "composition of a function with a 'constant' function that pushes a data value onto a stack". That led to the subsequent discovery that the data stack is extra "scaffolding" that can be removed: using prefix notation instead of postfix allows the program to be represented in memory as an actual composition of partially applied functions, each of which takes the remainder of the program as an argument and returns an output program. This led to the creation of Om [1], which I believe is the "most concatenative" language for this reason.
I remember discovering the Joy language (and combinatory logic) and being blown away by the elegance of being able to express programs just by composing functions. It was a pretty big epiphany to learn that when functions pop arguments from and push results onto a stack, the "application of a function to a data value" could be treated equivalently to "composition of a function with a 'constant' function that pushes a data value onto a stack". That led to the subsequent discovery that the data stack is extra "scaffolding" that can be removed: using prefix notation instead of postfix allows the program to be represented in memory as an actual composition of partially applied functions, each of which takes the remainder of the program as an argument and returns an output program. This led to the creation of Om [1], which I believe is the "most concatenative" language for this reason.
[1] http://om-language.org