Loon programming language
Ranked 61 of 163 programming languages by recommenders
A minimal Lisp with ownership-based safety and type inference that hides types from view, praised for elegance and polish. Common caveats are the bracket syntax and that it is not yet optimised for speed.
A minimal Lisp with ownership-based safety and type inference that hides types from view, praised for elegance and polish. Common caveats are the bracket syntax and that it is not yet optimised for speed.
26 people gave an opinion
- recommend it
- 21
- criticize it
- 5
- approval share
- 81%
Recommended in 3 of 13 months
- November 2025: not recommended
- December 2025: not recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: not recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: not recommended
- September 2026: not recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it doesn’t carry the badge
- 21 people recommend itNeeds 10 or more, met.
- 4.2 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 3 of 13 monthsNeeds 4 or more, not met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Types inferred, no annotations needed
“I like the ubiquitous type inference. I wish that part of Loon were less coupled to the allocation model though.”
Comment from 10 May 2026 in “Rust but Lisp” “I like types being invisible. Square brackets feels like a needless change.”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “everything is typed, but I don't need to annotate”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” Cool, promising concept
“Loon looks very cool, I didn't expect something like that to appear at all.”
Comment from 23 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “looks like it could just flat out become my favorite language.”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “Honestly, that's very cool”
Comment from 10 May 2026 in “Rust but Lisp” Ownership model beyond Rust syntax
“a Lisp built around the concept of ownership is much more interesting than just a way to write Rust via S-expressions”
Comment from 10 May 2026 in “Rust but Lisp” “takes heavy inspiration from Rust”
Comment from 10 May 2026 in “Rust but Lisp” Polished with good docs
“I love this! The docs are really good and I am looking forward to playing with this.”
Comment from 22 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “It’s rare that something this new is this polished.”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects”
What people warn about
Each mark is one comment
Bracket syntax disliked
“I don't love the brackets syntax, or the [op val1 val2] ([* x x]) style”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “I don't love the brackets syntax”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “I like types being invisible. Square brackets feels like a needless change.”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” - Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects”
Slow and not yet optimised
“Definitely cool in concept, but very performance-intensive and slow.”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “it demonstrates that the language works, but its not optimised yet”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” Examples don't run correctly
“these below doesn't run correctly”
Comment from 22 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects” “Unfortunately it seems like this doesn't currently work as expected when I use it in the playground”
Comment from 21 Feb 2026 in “Loon: A functional lang with invisible types, safe ownership, and alg. effects”
Other programming languages people recommend
The four most recommended other programming languages, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
See all 163 programming languages, rankedWhat people said
24 of the 29 comments that mention it, newest first. Each links to the original comment.
“they're building on top of the current jank APIs we have”
“I like it but confusing that there's also a similar but different loonlang.org.”
“The website seems to have some bugs on mobile, seen on Chrome 147.0.7727.137”
“I like the ubiquitous type inference. I wish that part of Loon were less coupled to the allocation model though.”
“Honestly, that's very cool”
“a Lisp built around the concept of ownership is much more interesting than just a way to write Rust via S-expressions”
“takes heavy inspiration from Rust”
“Loon looks very cool, I didn't expect something like that to appear at all.”
“I love this! The docs are really good and I am looking forward to playing with this.”
“these below doesn't run correctly”
“the explanations of the semantics could be improved”
“It’s rare that something this new is this polished.”
“It looks like an elegant, minimal selection of things existing languages already do well, while cutting out a lot of cruft.”
“it demonstrates that the language works, but its not optimised yet”
“Nobody really wants to write `[* 5 5]` do they?”
“this is a week-old project, with every single commit written by Claude”
“Definitely cool in concept, but very performance-intensive and slow.”
“Unfortunately it seems like this doesn't currently work as expected when I use it in the playground”
“I don't love the brackets syntax, or the [op val1 val2] ([* x x]) style”
“I like types being invisible. Square brackets feels like a needless change.”
“I don't love the brackets syntax”
“looks like it could just flat out become my favorite language.”
“I do wonder why they've leaned so hard into talking about the type system being out of sight.”
“everything is typed, but I don't need to annotate”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.