Circa is a programming language designed for for rapid prototyping by @andyfischer.

The intro page has some good information and the syntax example highlights some interesting ideas:

-- The @ operator is some syntactic sugar for rebinding
-- an identifier to the result of the overall statement.
-- These two lines do exactly the same thing:
my_number = max(my_number, 40)
max(@my_number, 40)

-- Lists are indicated by []s
-- List arguments also can be separated
-- by commas or semicolons or spaces
names = ['Absalom','Bouffant','Chilton']
numbers = [1 2 3]
orders = [locate; evacuate; exterminate]

Looks neat!