Snap! == Scheme ** Scratch
Snap! is a blocks based visual programming language like (and inspired by) Scratch, but with the full power of Scheme, an undiluted superset of Logo's and Scratch's capabilities, including user defined blocks, closures, and even continuations!
More about Snap!:
https://news.ycombinator.com/item?id=20309162
>One of the coolest ways to learn programming I've ever seen is the Snap! visual programming language, which is written in JavaScript and runs in the browser. https://snap.berkeley.edu
>It's the culmination of years of work by Brian Harvey and Jens Mönig and other Smalltalk and education experts. It benefits from their experience and expert understanding about constructionist education, Smalltalk, Scratch, E-Toys, Lisp, Logo, Star Logo, and many other excellent systems.
>Snap! takes the best ideas, then freshly and coherently synthesizes them into a visual programming language that kids can use, but is also satisfying to professional programmers, with all the power of Scheme (lexical closures, special forms, macros, continuations, user defined functions and control structures), but deeply integrating and leveraging the web browser and the internet (JavaScript primitives, everything is a first class object, dynamically loaded extensions, etc).
https://news.ycombinator.com/item?id=23053999
>Snap! has the full power of Scheme (first class functions, user defined blocks, recursion, closures, continuations, JavaScript integration, etc), with a visual block syntax and playful graphical environment with turtle graphics like Scratch.
>The following post is a couple years old, but maybe somebody can provide some updates and recent info!
>Edit: I should have RTFA first, which is totally up to date, just published in 2020, from the turtle's mouth:
https://escholarship.org/uc/item/1623m1p3
>Brian Harvey’s Personal Narrative on Snap!: Scheme Disguised as Scratch
>In 2009, the University of California, Berkeley, was one of several universities developing a new kind of introductory computer science course, meant for non-CS majors, to include aspects of the social implications of computing along with the programming content. Scratch wasn’t quite expressive enough to support such a course (it lacked the ability to write recursive functions), soProf. Daniel Garcia and I thought “What’s the smallest change we could make to Scratch to make it usable in our course?” After 20 years teaching Structure and Interpretation of Computer Programs [Abelson et al.1984], the best computer science text ever written, I knew that the answer to “what’s the smallest change” is generally “add lambda.” I joined forces with German programmer Jens Mönig, who had developed BYOB (Build Your Own Blocks), an extension to Scratch with custom (user-defined) blocks, including reporters and predicates. [...]
Anybody else in Barcelona for Snap!Con this week? Let's meet up and say hi!