{"slug": "keykos", "name": "KeyKOS", "category": "os", "category_name": "Operating systems and desktop", "description": "", "recommenders": 3, "commenters": 5, "warners": 0, "score": 3.079, "rising": -0.98, "first": "2025-12-14", "latest": "2026-07-19", "why": "I find the emphasis on minimizing process and kernel state", "why_is_quote": true, "has_verdict": false, "sentiment": {"recommend": 3, "neutral": 2, "compare": 0, "warn": 0}, "spark": [0, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0], "listed": true, "loved": [], "caveat": "", "short_quote": "I find the emphasis on minimizing process and kernel state", "kind": "", "icon": false, "domain": "wikipedia.org", "github_repo": null, "official_url": "", "pricing": "", "aliases": ["KeyKOS"], "verdict": null, "praise": [{"label": "", "summary": "", "quotes": [{"id": 777996368, "item_id": 48624773, "url": "https://news.ycombinator.com/item?id=48624773", "by": "mikewarot", "date": "2026-06-21", "version": null, "stance": "recommend", "quote": "solved computer security about 40 years ago[2]", "excerpt": "It's sad that they did the research[1] and solved computer security about 40 years ago[2], and then proceeded to lose that hard won knowledge over time. [1] https://csrc.nist.rip/publications/history/index_1.html [2] https://en.wikipedia.org/wiki/KeyKOS", "context": "", "use_case": "", "switched_from": "", "story": "NSA director: 'Mythos \"broke into almost all of our classified systems in hours\""}, {"id": 740463552, "item_id": 46278972, "url": "https://news.ycombinator.com/item?id=46278972", "by": "naasking", "date": "2025-12-15", "version": null, "stance": "recommend", "quote": "KeyKOS solved this issue in the 1970s.", "excerpt": "> Otherwise it would not be a viable alternative to ACLs. I just want to point out that this is vastly overblown IMO. Typical ACL systems are just organized differently than capability systems that follow POLA. In the former, permissions to a number of objects are widely shared across many different subjects, and so fine-grained grant and revocation for subjects seem natural. It thus also seems natural to think that ", "context": "", "use_case": "Capability-based operating system", "switched_from": "", "story": "CapROS: Capability-Based Reliable Operating System"}, {"id": 740337680, "item_id": 46271105, "url": "https://news.ycombinator.com/item?id=46271105", "by": "retrac", "date": "2025-12-14", "version": null, "stance": "recommend", "quote": "I find the emphasis on minimizing process and kernel state", "excerpt": "I've written a little bit before about KeyKOS/GNOSIS, which is the capability operating system used by Tymshare to host their timesharing language services on IBM mainframes, in the 70s and 80s. From a comment 3 years ago I'll just repost the relevant part: > KeyKOS (developed by Tymshare for their commercial computing services in the 1970s) - A capability operating system. If everything in UNIX was a file, then ever", "context": "", "use_case": "Capability-based operating system", "switched_from": "", "story": "CapROS: Capability-Based Reliable Operating System"}]}], "caveats": [], "who": [], "tags": [], "use_cases": ["capability-based operating system", "single-level store os example"], "compared": [], "makers": [], "threads": [{"url": "https://news.ycombinator.com/item?id=46268869", "title": "CapROS: Capability-Based Reliable Operating System", "mentions": 3}, {"url": "https://news.ycombinator.com/item?id=48962758", "title": "Hardcore IndieWeb: Run your own website 100% independently for only $0.01/day", "mentions": 1}, {"url": "https://news.ycombinator.com/item?id=48617278", "title": "NSA director: 'Mythos \"broke into almost all of our classified systems in hours\"", "mentions": 1}], "sentiment_by_month": {"2025-11": {}, "2025-12": {"recommend": 2, "neutral": 1}, "2026-01": {}, "2026-02": {}, "2026-03": {}, "2026-04": {}, "2026-05": {}, "2026-06": {"recommend": 1}, "2026-07": {"neutral": 1}, "2026-08": {}, "2026-09": {}, "2026-10": {}}, "versions": [], "version_unnamed": 0, "family_ref": null, "runs_on": null, "lines": [], "quotes": [{"id": 783504496, "item_id": 48969031, "url": "https://news.ycombinator.com/item?id=48969031", "by": "inigyou", "date": "2026-07-19", "version": null, "stance": "neutral", "quote": "KeyKOS is an example of this and you can read papers about it and its Unix emulation layer.", "excerpt": "how would any alternative design prevent intended behavior? But the most obvious alternative to a filesystem would be formatting a whole hard drive as an sqlite database. Obviously it would be a radical rethink in OS design. There are also \"single-level stores\" from the last millennium - designs where there is no separation between volatile and nonvolatile storage. All memory in these systems is treated as nonvolatil", "context": "", "use_case": "single-level store OS example", "switched_from": "", "story": "Hardcore IndieWeb: Run your own website 100% independently for only $0.01/day"}, {"id": 777996368, "item_id": 48624773, "url": "https://news.ycombinator.com/item?id=48624773", "by": "mikewarot", "date": "2026-06-21", "version": null, "stance": "recommend", "quote": "solved computer security about 40 years ago[2]", "excerpt": "It's sad that they did the research[1] and solved computer security about 40 years ago[2], and then proceeded to lose that hard won knowledge over time. [1] https://csrc.nist.rip/publications/history/index_1.html [2] https://en.wikipedia.org/wiki/KeyKOS", "context": "", "use_case": "", "switched_from": "", "story": "NSA director: 'Mythos \"broke into almost all of our classified systems in hours\""}, {"id": 740566656, "item_id": 46285416, "url": "https://news.ycombinator.com/item?id=46285416", "by": "kragen", "date": "2025-12-15", "version": null, "stance": "neutral", "quote": "", "excerpt": "Did they actually deploy GNOSIS at Tymshare? I hadn't heard that. I thought that the reason they spun out Key Logic was that Norm hadn't convinced Tymshare management to deploy GNOSIS. For example, in https://conservancy.umn.edu/server/api/core/bitstreams/a39e58bc-2e03-4a34-9a5e-7bd138835809/content p. 37, he says: > That was their [Derwent's] idea. I thought it was very clever and we realized that we couldn\u2019t do it ", "context": "", "use_case": "", "switched_from": "", "story": "CapROS: Capability-Based Reliable Operating System"}, {"id": 740463552, "item_id": 46278972, "url": "https://news.ycombinator.com/item?id=46278972", "by": "naasking", "date": "2025-12-15", "version": null, "stance": "recommend", "quote": "KeyKOS solved this issue in the 1970s.", "excerpt": "> Otherwise it would not be a viable alternative to ACLs. I just want to point out that this is vastly overblown IMO. Typical ACL systems are just organized differently than capability systems that follow POLA. In the former, permissions to a number of objects are widely shared across many different subjects, and so fine-grained grant and revocation for subjects seem natural. It thus also seems natural to think that ", "context": "", "use_case": "Capability-based operating system", "switched_from": "", "story": "CapROS: Capability-Based Reliable Operating System"}, {"id": 740337680, "item_id": 46271105, "url": "https://news.ycombinator.com/item?id=46271105", "by": "retrac", "date": "2025-12-14", "version": null, "stance": "recommend", "quote": "I find the emphasis on minimizing process and kernel state", "excerpt": "I've written a little bit before about KeyKOS/GNOSIS, which is the capability operating system used by Tymshare to host their timesharing language services on IBM mainframes, in the 70s and 80s. From a comment 3 years ago I'll just repost the relevant part: > KeyKOS (developed by Tymshare for their commercial computing services in the 1970s) - A capability operating system. If everything in UNIX was a file, then ever", "context": "", "use_case": "Capability-based operating system", "switched_from": "", "story": "CapROS: Capability-Based Reliable Operating System"}]}