[pavlov]

My point was that the world around will change, and at some point the declarative language that seemed so succinct will become clunky and inadequate to express the new requirements.

Java+XML really is the poster child for this. There was a time when it was the fresh declarative kid. React will most likely follow a similar path, not through any fault of its own.

[dualogy]

> My point was that the world around will change

Same will happen to your Swift or Android-Java codebases though. Go try to build and run on your 2015-17 machine+OS+devenv any just-slightly-real-world-beyond-hello-world run-off-the-mill 15-year old Visual Studio 6 line-of-biz (or other) codebase right now.. or whatever they used on Macs back then (I'd imagine the compatibility story for pre-OSX stuff is maybe even slightly worse than in MS land). Software that's meant to survive is meant to be maintained, I guess.

Or the server side of a web app? What's it gonna be, CGI or ASP 3 or PHP 3.. always the same story.

Bringing up HTML/JS/CSS from those days to function (though not shine) for today's requirements might prove comparatively tame by comparison =)

[kitsunesoba]

I can’t speak much for the rest, but old Mac codebases in particular hold up better than you might think. You can write an application that runs on every version of Mac OS from 1.0 (circa 1985) up to High Sierra with just a handful of conditionals through the use of Carbon [0]. Porting pre-OS X software should be similarly simple, given that it’s written in C or C++ (Pascal was somewhat popular for classic Mac apps, not sure what getting that code running on modern machines would look like).

When it comes to “new world” Mac stuff, the things keeping something written for OS X 10.0 from running on modern macOS have more to do with API deprecations than anything else. Objective-C is still widely used and is well supported (even with Swift’s growing popularity), so usually getting an old codebase of this nature running just means fixing a couple of deprecation errors, fixing a bunch of warnings, and hitting compile. The nature of change in the native sphere has largely been evolutionary, not revolutionary, so it’s largely stayed the same with new things being added. It’s not like the web where wheel reinvention and fads are a constant.

[0] http://blog.steventroughtonsmith.com/post/109040361205/mpw-c...