# Stack Overflow founding date

entity: /record/stack-overflow.md  
predicate: founded  
page: /record/stack-overflow/founded  
as_of: 2026-11-03  

As of November 3, 2026, Stack Overflow's founding date on the AsOf record is September 15, 2008, dated September 15, 2008, from 2 secondary sources (blog.codinghorror.com and joelonsoftware.com). The record holds 1 claim on Stack Overflow's founding date, 1 still open and 0 superseded, each dated and sourced; a replaced value is closed with an end date, never deleted.

## Current founding date

What the record asserts on 2026-11-03.

- [Stack Overflow](/record/stack-overflow.md) | founded | 2008-09-15 | valid 2008-09-15 to present | conf 0.85 | valid | [clm_376D9F72CCD4](/claim/clm_376D9F72CCD4.md)
  sources: https://blog.codinghorror.com/stack-overflow-none-of-us-is-as-dumb-as-all-of-us/, http://www.joelonsoftware.com/items/2008/09/15.html, https://www.wikidata.org/wiki/Q549037

## Every dated value

One claim per line, oldest first. Superseded claims stay visible.

- [Stack Overflow](/record/stack-overflow.md) | founded | 2008-09-15 | valid 2008-09-15 to present | conf 0.85 | valid | [clm_376D9F72CCD4](/claim/clm_376D9F72CCD4.md)
  sources: https://blog.codinghorror.com/stack-overflow-none-of-us-is-as-dumb-as-all-of-us/, http://www.joelonsoftware.com/items/2008/09/15.html, https://www.wikidata.org/wiki/Q549037

## Questions this record answers

### What is Stack Overflow's current founding date?

September 15, 2008, dated September 15, 2008, from 2 secondary sources (blog.codinghorror.com and joelonsoftware.com). The record asserts this claim as of November 3, 2026 (status valid, confidence 0.85).


## Get this data

- JSON: /v1/entities/stack-overflow/founded (this fact) · /v1/entities/stack-overflow?predicates=founded (with the entity's coverage; add as_of=YYYY-MM-DD for a date)
- MCP: timeline(entity: "stack-overflow", predicates: ["founded"]) for every dated value · fetch(id: "/record/stack-overflow/founded.md") for this page
- Entity twin: /record/stack-overflow.md · timeline: /timelines/stack-overflow.md

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AsOf is a temporal fact ledger: a structured, dated, sourced record of what is true and what changed, built for AI retrieval.