Helix wants to be Emacs. Ever since they decided to use a built-in Lisp dialect called "Steel" for scripting and become the next Emacs, not the next Neovim, I stopped following it. I love Lisp, I wrote so much code in Lisp in the '80s and early '90s, but that was another millennium! It's 2025 now, and just because it's easy to write Lisp interpreters doesn't mean we should use them. In fact, maybe Forth is even easier than Lisp... well, not really.
I'm not sure why you think Lisp makes this "emacs" unless you're worried it'll fall flat because most Lisp-interested folks would find emacs more full featured? I'm not sure if a Scheme is particularly different than neovim's Lua. I'll be honest though I'm not sure how deeply Steel is integrated into Helix.
It's not integrated at all right now. It's still sitting in a feature branch unfortunately.
Ah I thought the big branch finally got merged.
Not yet. PR is still open and waiting for someone from the team to review. I suspect this won't be an easy thing.
<Controversial opinion> Computer scientist and mathematicians love lisp/scheme, everyone else hates it. The problem is that the syntax, concepts etc are so different that you really have to learn the language to make even small changes. Just reading prefix notation takes quite a bit of adjustment. When I was using emacs doom every time I changed my config felt like stabbing in the dark (hence I moved away). In contrast I could make lua changes (without any prior lua knowledge) without any problems.
I don't want to learn a new language just to configure my editor.
So by choosing scheme they essentially say this is an editor for computer scientists only. </controversial opinion>
Lisps make great configuration languages because of how dynamic they are. It's like Javascript on steroids. Redefine core symbols. Modify a syntax form and reevaluate all of your code so that it does one thing in one environment and something else in a different one. When building large software in a team this can be a big drag; learning some weird syntax form that a coworker merged in that you didn't review can be a headache and when everyone makes their own design patterns, the codebase becomes a mess.
But when you're just configuring software this heavily dynamic nature becomes a strength. I just need to build the abstractions in my config that I need, nobody else. It's easy to poke around in and spend a few minutes writing and iterating on code to get the config I want.
I agree that the prefix notation and the soup of parentheses give it a higher learning curve than something like Lua which is easily understandable if you have experience in pretty much any modern programming language. But it's not the mathematical/computational purity that makes Lisps appealing, it's their highly dynamic nature.
It's very hard to argue the plugin system has made Helix anything in particular, considering it is not merged yet. Approximately nobody's experience of Helix up to this point has been influenced by this choice.
Don't worry, Fennel compiles to Lua so you can keep configuring Neovim with a Lisp dialect too!
I'm not sure why you think Lisp is somehow "outdated". It is a perfectly modern programming language and new Lisp code gets written at startups today in 2025.