[mattparas]

Hopefully the linked README provides a general overview (I know I need to write some more documentation!), but Steel is an implementation of the scheme programming language (not entirely compliant yet, but aiming for R5RS and R7RS compliance). It can be used as a standalone language via the interpreter/repl (like Python or Racket), or it can be embedded inside applications, like Lua. There are hundreds (thousands, probably) of embeddable languages, each with their own flavor - see a list compiled here for example https://github.com/dbohdan/embedded-scripting-languages

Use cases are generally for either configuration, scripting, or plugins - so scripting in games, or adding extensions to your text editor without having to use FFI or RPC + serializing a bunch of data. The advantage it has over using dynamic libraries (in general) is it runs in the same process, and can access the internal data structures directly without a lot of ceremony involved. The downside is that it is typically not as fast as native code unless a JIT is involved.

Javascript is an example of an embedded scripting, where the browser is the host application.

[I_am_tiberius]

Understood. Thank you for the summary!