Yes, CoffeeScript, in 2009. Despite being a modest, fun experiment in stripping JavaScript down to a minimal skin, and without any corporate backing, it wound up catching on a little bit. Thanks to the hard work of Geoffrey Booth and Simon Lydell, among others, there's a new "V2" version that includes many ES6 and 7 features that's almost ready to go: http://coffeescript.org/v2/ CoffeeScript was designed extremely co…
So, extremely liberal, you said... :-) Thinking about this I started to wonder about other systems producing a similar output to the trio html/css/js. I realized PostScript is such a system, but for fixed size documents. People actually explored using PostScript for GUI applications in the past, as described in [1]. At some point I'd like to explore [2] and [3] to see if some of the ideas could be modernized and adapted for the web.
1: https://en.wikipedia.org/wiki/PostScript#Use_as_a_display_sy... 2: https://en.wikipedia.org/wiki/Display_PostScript 3: https://en.wikipedia.org/wiki/NeWS