# What is the greatest (most influential, whatever) computer program ever written?

**URL:** <https://boards.straightdope.com/t/what-is-the-greatest-most-influential-whatever-computer-program-ever-written/830575>\
**Category:** In My Humble Opinion\
**Created:** [March 5, 2019, 3:53pm UTC](https://boards.straightdope.com/t/what-is-the-greatest-most-influential-whatever-computer-program-ever-written/830575 "2019-03-05T15:53:19Z")\
**Posts on this page:** 3\
**Page:** 7

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**Author:** ![JohnT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnt/32/15048_2.png) [@JohnT](https://boards.straightdope.com/u/JohnT)\
**Post date:** [March 10, 2019, 3:38pm UTC](https://boards.straightdope.com/t/what-is-the-greatest-most-influential-whatever-computer-program-ever-written/830575/121 "2019-03-10T15:38:25Z")

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Sabre is a publicly traded corporation (NASDAQ, SABR) with nearly $4b in annual revenues.

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**Author:** ![RaftPeople](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@RaftPeople](https://boards.straightdope.com/u/RaftPeople)\
**Post date:** [March 10, 2019, 5:12pm UTC](https://boards.straightdope.com/t/what-is-the-greatest-most-influential-whatever-computer-program-ever-written/830575/122 "2019-03-10T17:12:53Z")

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A pretty significant chunk of software that altered the computing landscape was the cloned BIOS (Phoenix) that was then licensed to the PC clone mfgrs.

It was a critical first step that led to the explosion in the PC market in the 80’s.

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**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\
**Post date:** [March 10, 2019, 9:10pm UTC](https://boards.straightdope.com/t/what-is-the-greatest-most-influential-whatever-computer-program-ever-written/830575/123 "2019-03-10T21:10:40Z")

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> [@Marvin\_the\_Martian](#):
>
> SPICE (Simulation Program with Integrated Circuit Emphasis) is a circuit simulation program developed at UC Berkeley in the early 70s. It revolutionized the development of integrated circuits, allowing design of circuits which were too complex for hand analysis. It remains an industry standard more than 45 years after its initial release. Literally every integrated circuit in use today was at least partially designed using SPICE (likely one of the commercial variants like HSPICE) or SPICE-like competitors (SPECTRE or ELDO).

> [@JohnT](#):
>
> This is an awesome answer. Don’t know if it’s the “greatest” program written, but I had no idea about this and, given your description and its impact on the complexity of software which _could_ be written, I could definitely see SPICE on a “top 100” list.

It goes much farther than complexity of software that could be written. It expanded the complexity of electronics that could be designed by orders of magnitude. Not just microprocessors and memories, but analog and RF circuits as well. The entire microelectronics industry is based on this program and its generations of upgrades and improvements.

Of course, the development of this sort of software was inevitable, it is based on numerical methods that had been under development for decades. But someone had to be first, and many successors used that original program (it was one of the first open-source programs) as a starting point for their own versions. At some point it was ported from Fortran to C byte the original development team -I am certain chunks of this C code are still in use.

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