This made me smile.. So legacy applications are going away? Like the one that I maintain at work, written in (mainframe) SAS, which is so-called 4th generation

This made me smile.. So legacy applications are going away? Like the one that I maintain at work, written in (mainframe) SAS, which is so-called 4th generation programming language, invented with a promise of users just "telling" computers what to do in a "natural" language. Don't get me wrong, I like the promise. It's what Facebook is doing with Haxl, which is a domain-specific language for content filtering, written in Haskell. Unfortunately, the needs of users will often grow and the language will have to become Turing-complete (like for example, HTML/CSS was extended with Javascript), if it wasn't already, and also will have to become extensible by user routines written in mainstream language. And then you get messy, "legacy" (as they are called after few years) systems.