I wish people would stop publishing me-too languages that implement, for the umpteenth time, the same concepts we have had for 40 years or more. I mean, if you just to learn from the experience of creating a language, that's fine, but you probably won't get much from publishing it.
If one intends to publish a language, it seems to me one should focus on crafting a language that explores something new. That new concepts do not have to be very refined or complex, but your language stand a much better chance of being picked up and refined if it implements the germ of some interesting new idea.
Of the top of my head, here are some concepts [1] I'm trying to explore (cross posted from another comment of mine), which might provide inspiration for others:
- Dependent types, with no real distinction between values and types (At a certain point, Typescript’s type system begins to look like a separate Turing-complete language within a language. It’s probably time to do away with this dichotomy entirely somehow)
- JSX built-in without the need for any React-like dependency (No need to use it if you don’t like it; in the general sense, it’s just syntactic sugar for composing function invocations)
- Localizable or customizable keywords/operators, with automatic translation provided by an utility or language server (Why should programming languages be tools of cultural hegemony?)
- Generic object literals (Why should generic type inference be limited to functions?)
- Deep support for an alternative to exceptions using a Failable<TResult, TError> type
1. They may not be totally new concepts (as in some non-mainstream languages might implement them to some extent), but they are sufficiently of the beaten track that they are a rich source for exploring all kinds of interesting features.