2003: https://www.microsoft.com/en-us/research/publication/a-user-centred-approach-to-functions-in-excel/ https://www.microsoft.com/en-us/research/publication/a

2003: https://www.microsoft.com/en-us/research/publication/a-user-centred-approach-to-functions-in-excel/ https://www.microsoft.com/en-us/research/publication/a-user-... 2021: https://www.microsoft.com/en-us/research/blog/lambda-the-ultimatae-excel-worksheet-function/ https://www.microsoft.com/en-us/research/blog/lambda-the-ult... Not quite 25 years, but it was a paper published by microsoft research, about a microsoft project, that took 18 years to be implemented.