The esoteric programming language Whitespace uses only three characters: tabs, spaces, and line breaks. That makes it effectively invisible to the naked eye.
More than a year ago I wrote about Shakespeare, the programming language made entirely of text that looks like Shakespearean plays. Shakespeare is just one of several so-called esoteric programming languages. They’re a kind of performance art, a way to push the boundaries of programming and entertain or baffle us.
Yep, in Whitespace every character is ignored except for the blank ones: the spaces, the tabs, and the linefeeds (the line breaks). If you think that’s not enough to make a programming language, remember that binary code gets by with just 0s and 1s. Here’s a sample of Whitespace, the first line of the instructions to print “Hello, World!”:
Haha, sorry, I couldn’t resist. Here’s a non-invisible version:
The coolest thing about this programming language is that it could conceivably be slotted into the gaps of another language’s code – that other language using the text and Whitespace using the spaces.