Ask HN: Unusual programming language choices?

Yesterday I came across some QBasic posts and found about "Black Annex" game which passed Steam Greenlight and was actually written in QBasic with more than 12.000 lines of source code.

Anyway, I am curious about popular and/or relatively successful projects that were written in programming languages which are not considered perfect fit or usual choice by other developers (for that particular application) or simply not modern enough?

It can be from any segment: console, web, GUI, server-side, game etc.

Thanks.