R has "first class environments + fexpr equivalents + almost lexical scope". Wow, newLisp was the only language I knew with fexprs.
Related Posts
Are there any package managers that treat changelogs as a first class concept?
I end up looking for a CHANGELOG.md or a CHANGES.txt in the source code repository every time. The lack of standard prevents package hosting services being able to show changes.
What are the most interesting upcoming scripting languages? Scripting remains an important part of the programming language ecosystem.
Optimise time to first feature. Allow mutation of the running system to experiment. Interactive inspection of data.
It's weird that GitHub shows time since the last commit, but not time since the first commit. It's a nice way of seeing how mature a project is.