Several references to the quote "There are only two hard things in Computer Science: cache invalidation and naming things" can be found, such as Martin Fowler's blog and others.

I'm unable to find the source of this quote, has he ever said it?

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    Me, I'm interested in who came up with the variant: "There are only two hard things in Computer Science: cache invalidation, naming things, and off-by-one errors." – Doug Kavendek Mar 8 '14 at 5:15
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    Have you reached out to Netscape-ians? Phil was Principal Curmudgeon there. lacquer.fi/pauli/blog/2011/05/… – LAFK says Reinstate Monica Nov 23 '14 at 18:17
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    I have this same question, and specifically, when did he say it? – DrZ214 Nov 24 '15 at 8:43
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    someone please post a huge bounty.... – Jason S Feb 17 '16 at 17:45
  • @DrZ214 1996 or 1997, as Tim Bray remembers – dumbledad Jan 5 '17 at 15:39

As his only son, and colleague with him at Netscape from 95-97, I can attest that my dad did indeed throw that quote around, on more than one occasion. I'm fairly confident that he originated it (he was fond of coming up with clever quippets), though I haven't been able to figure out how it disseminated so widely over the past couple of decades. I'll keep looking around in old web archives and mails to see if I can dig something up.

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    Welcome to Skeptics! It is always exciting when someone directly involved in an issue graces us with an answer, but unfortunately there are so many trolls on the Internet, we can't accept an anecdote at face value. If you can find a reference in an old web archive, or link to somewhere where you say this and we can verify who you are, that would be fantastic. Thanks! – Oddthinking Aug 11 '17 at 2:38
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    If you'd like to share this anecdote on a blog or other website of yours, then that website can be quoted and used as a reference for your answer here. Plus, it'd have the added advantage of sharing the information more broadly! – Nat Jan 29 '18 at 1:16
  • How can I cite it in a paper I'm writing? – Shamoon May 30 '19 at 13:10
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    I was going to say that we should add "identity verification" to the original list of things that are hard, but I suppose this can fall under "naming things". :-) – Neil Laslett Apr 29 at 2:22

Tim Bray says on Twitter:

Phil [Karlton] said it, I reported it, someone else added on the “off-by-one”.

Leon Bambrick replies that he added off-by-one.

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    I'd like a little bit more than just one person saying he "reported it". Where did he report it? I found only tbray.org/ongoing/When/200x/2005/12/23/UPI which is dated 2005 but a google search for "cache invalidation and naming things" returns random results as far back as February 2001. – Vitor De Mario Jan 21 '15 at 21:27

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