SPADE is a programming language first conceived in August 2018 by User:Swampie27782 and User:KiloByte?. It was made for a 12th grade computer science project in order to create a compiler for it in C++, making it one of the only languages to have been created purely to be interpreted by another language. The full form of SPADE is, during normal conversation, Simple Parsing Algorithm Developed using C++ Expressions. However, its official expansion is Sabaton Pannikin Argentiferous Demisang Exaugurate. As you can see, this expansion makes far more sense.
Further edits forthcoming! For a teaser into the language (a quine program),
var a. a : "\\var a\.\\na \\: \\"\" ~a \"\\"\.\\np\\rint \\"\" a\.". print "\var a.\na \: \"" ~a "\".\np\rint \"" a.
First one to figure out what it does gets a reward! (It'll probably be like a thumbs up or something.)