{"slug": "f", "name": "F*", "category": "other", "category_name": "Other software", "description": "", "recommenders": 3, "commenters": 4, "warners": 0, "score": 2.782, "rising": -0.98, "first": "2025-11-02", "latest": "2026-09-08", "why": "F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 3, "neutral": 0, "compare": 1, "warn": 0}, "spark": [1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0], "listed": true, "loved": [], "caveat": "", "short_quote": "F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification", "kind": "", "icon": true, "domain": "fstar-lang.org", "github_repo": null, "official_url": "https://fstar-lang.org", "pricing": "", "aliases": ["F*"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 785779424, "item_id": 49111214, "url": "https://news.ycombinator.com/item?id=49111214", "by": "ducktective", "date": "2026-07-30", "version": null, "stance": "recommend", "quote": "doesn't it seem to be a more appropriate option", "excerpt": "Recent posts on formal proofs usually talk about Lean, Rocq, Isabelle and (due to this post) Metamath. What do people think of F* [1]? At least, for non-mathematics projects, doesn't it seem to be a more appropriate option [2]? It seems even the CS community is gravitating towards Lean. [1] https://fstar-lang.org/ [2] https://fstarlang.github.io/lowstar/html/Introduction.html", "context": "", "use_case": "", "switched_from": "", "story": "Are We Stuck with Lean?"}, {"id": 753105361, "item_id": 47069085, "url": "https://news.ycombinator.com/item?id=47069085", "by": "nextos", "date": "2026-02-18", "version": null, "stance": "recommend", "quote": "F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification", "excerpt": "If verification is the goal, but you don't want to learn theorem proving yet, Dafny is really approachable and practical [1]. F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification [2]. Why3, Rocq and Agda are other obvious contenders. [1] https://dafny.org/latest/OnlineTutorial/guide [2] https://fstar-lang.org/tutorial", "context": "", "use_case": "software verification", "switched_from": "", "story": "Learning Lean: Part 1"}, {"id": 732701712, "item_id": 45793857, "url": "https://news.ycombinator.com/item?id=45793857", "by": "tombert", "date": "2025-11-02", "version": null, "stance": "recommend", "quote": "I was really pushing for using F*, but it was impossible to get any buy-in from coworkers", "excerpt": "My abandoned PhD was in formal methods and I find dependent types to be pretty neat, but every time I've tried using a dependently typed language for anything it's always been an uphill battle. When I used to do F# for a living, I was really pushing for using F*, but it was impossible to get any buy-in from coworkers because the learning curve was comparatively steep. I probably should have pushed a bit more, but I f", "context": "formal methods background, F# developer", "use_case": "formal verification at work", "switched_from": "", "story": "Why don't you use dependent types?"}]}], "caveats": [], "who": [{"by": "tombert", "context": "formal methods background, F# developer", "url": "https://news.ycombinator.com/item?id=45793857", "date": "2025-11-02"}], "tags": [], "use_cases": ["software verification", "formal verification at work"], "compared": [{"slug": "lean", "name": "Lean", "co": 2, "switched_from": 0, "switched_to": 0}], "makers": [], "threads": [{"url": "https://news.ycombinator.com/item?id=49612191", "title": "C*: Unifying Programming and Verification in C (2025)", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=49108678", "title": "Are We Stuck with Lean?", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=47022604", "title": "Learning Lean: Part 1", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=45790827", "title": "Why don't you use dependent types?", "mentions": 1}], "sentiment_by_month": {"2025-11": {"recommend": 1}, "2025-12": {}, "2026-01": {}, "2026-02": {"recommend": 1}, "2026-03": {}, "2026-04": {}, "2026-05": {}, "2026-06": {}, "2026-07": {"recommend": 1}, "2026-08": {}, "2026-09": {"compare": 1}, "2026-10": {}}, "versions": [], "version_unnamed": 0, "family_ref": null, "runs_on": null, "lines": [], "quotes": [{"id": 793804064, "item_id": 49612754, "url": "https://news.ycombinator.com/item?id=49612754", "by": "Taikonerd", "date": "2026-09-08", "version": null, "stance": "compare", "quote": "this sounds like F*, another proof-oriented language", "excerpt": "The authors cite this, but just to mention it: this sounds like F*, another proof-oriented language. (https://fstar-lang.org/) F* is in the ML family of languages, so it looks pretty different from C*.", "context": "", "use_case": "", "switched_from": "", "story": "C*: Unifying Programming and Verification in C (2025)"}, {"id": 785779424, "item_id": 49111214, "url": "https://news.ycombinator.com/item?id=49111214", "by": "ducktective", "date": "2026-07-30", "version": null, "stance": "recommend", "quote": "doesn't it seem to be a more appropriate option", "excerpt": "Recent posts on formal proofs usually talk about Lean, Rocq, Isabelle and (due to this post) Metamath. What do people think of F* [1]? At least, for non-mathematics projects, doesn't it seem to be a more appropriate option [2]? It seems even the CS community is gravitating towards Lean. [1] https://fstar-lang.org/ [2] https://fstarlang.github.io/lowstar/html/Introduction.html", "context": "", "use_case": "", "switched_from": "", "story": "Are We Stuck with Lean?"}, {"id": 753105361, "item_id": 47069085, "url": "https://news.ycombinator.com/item?id=47069085", "by": "nextos", "date": "2026-02-18", "version": null, "stance": "recommend", "quote": "F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification", "excerpt": "If verification is the goal, but you don't want to learn theorem proving yet, Dafny is really approachable and practical [1]. F* is also worth considering as a proof-oriented alternative to Isabelle that is focused on software verification [2]. Why3, Rocq and Agda are other obvious contenders. [1] https://dafny.org/latest/OnlineTutorial/guide [2] https://fstar-lang.org/tutorial", "context": "", "use_case": "software verification", "switched_from": "", "story": "Learning Lean: Part 1"}, {"id": 732701712, "item_id": 45793857, "url": "https://news.ycombinator.com/item?id=45793857", "by": "tombert", "date": "2025-11-02", "version": null, "stance": "recommend", "quote": "I was really pushing for using F*, but it was impossible to get any buy-in from coworkers", "excerpt": "My abandoned PhD was in formal methods and I find dependent types to be pretty neat, but every time I've tried using a dependently typed language for anything it's always been an uphill battle. When I used to do F# for a living, I was really pushing for using F*, but it was impossible to get any buy-in from coworkers because the learning curve was comparatively steep. I probably should have pushed a bit more, but I f", "context": "formal methods background, F# developer", "use_case": "formal verification at work", "switched_from": "", "story": "Why don't you use dependent types?"}]}