MISC: A homoiconic language based on maps
will.thimbleby.net
will.thimbleby.net
An elegant system for metadata which can be used to implement documentation, pretty printing, types, debugging, logging, and other such meta things.
Keyword arguments are baked in for free.
Direct read/write access to the environment as a map.
this is one of the things i like about Lua (which is listed there as a source of ideas)
i definitely don't like the choice of square brackets though, it's very ugly and hard to read. they should have stuck with parens