What features should a modern programming language have?

First Class Everything, Baby Undoubtedly, this is the way of the future. Making more stuff first class does nothing but make your programming language more powerful. You start with something like C or Java (pre-8), which have first class almost-nothing, and explode from there. Add first-class functions (and a ton of other stuff you can read about ) and you get languages like Haskell and the entire functional programming paradigm. Start making everything objects and making it all first class with decorators and extremely liberal syntax and you get Python. These languages are far more expressive and far more powerful than something like Java, because you can easily encapsulate and repeat design and execution patterns. If your language is really cool, you can even write abstractions on top of those patterns to get really amazing stuff. The rabbit hole goes much deeper, though. Adding first class functions and classes is a start, but there's much more you can do. Ask any Lisp programmer what his or her favorite thing about Lisp is, or what the most powerful thing about Lisp is, and they'll tell you Macros. Macros are a function of making the very language itself a first class object. Macros let you manipulate not just execution patterns, but entire program types. The more things you make first class, the more you can change and abstract and encapsulate to make your code clearer and easier to manage. With first class functions you can create higher order functions or monads, with first class classes and objects you can use decorators, with first class expressions you can modify your language on the fly. Ultimately, these are just higher levels of abstraction - calling something first class lets you build better abstractions on it. Better abstractions -> more productivity and cleaner, more concise and easily manageable code.

Not exactly language features, but there should be three things built into language: Standard build tools Standard package management system Standard deployment tools

HIgh level of abstraction to implement domain processes and structures.

If speed is at all important, a http://en.wikipedia.org/wiki/Memory_model_(programming) for threading to allow the language to take advantage of parallel platforms is essential.