| > A language by itself is almost never useful, every language needs a killer app, I don't understand why this myth is still around. C++ never had a killer app to start its momentum. Neither did Javascript. Nor Java really (or maybe applets, back in the days?). Languages can succeed on technical merits alone if they come out at the right time and fix real problems that programmers experience on current mainstream languages. |
1. Extreme compatibility with the current entrenched language so you can incrementally migrate. C++ from C. CoffeeScript and TypeScript from JavaScript. Kotlin from Java.
2. A killer app (well, framework). Rails for Ruby. WinForms for C#. Applets and J2EE for Java (later Android).
3. A new platform where you must use the language to target it. C for UNIX. Objective-C for iOS. JavaScript for the browser.
There are a few exceptions here and there, but the above are the typical well-trod paths to success for a language.