roc

Roc is a fast, friendly, functional programming language. The pitch is that you get syntax that stays out of your way (the Elm influence is obvious) without giving up the near-native speed that usually pushes people away from functional languages. Its standout idea is a split most languages don't make: you write pure logic in Roc, and a swappable "platform" underneath supplies everything that touches the outside world, files, network, screen. That lets a web-server platform and a CLI platform each tune performance for their domain, for free, from the app author's point of view. It's open source under a permissive license.

Here's the honest part, and it matters more than any feature. Roc is not ready. The team says so directly: there's no 0.1 release yet, and the current compiler, mid-rewrite into Zig, is in their own words suited for things like programming puzzles. This is pre-alpha. The credibility is real: Richard Feldman, the face of Elm, leads it, and it's backed by a nonprofit foundation with sustained, multi-year engineering behind it. But credibility is not readiness.

If you write functional code and like where this is going, experiment with it, follow it, maybe contribute. The closest comparisons are Elm (same creator, same friendliness, but Roc isn't locked to the browser), Gleam, Haskell, and OCaml. Anyone choosing between them today should know Roc is the youngest and least settled of the group.

The catch is simple: don't build anything you care about on Roc yet. You'd be signing up for breaking changes, a tiny platform ecosystem, and a compiler the team itself calls puzzle-grade. It's a language to watch, not to ship.