Case study

O21: a black-box remake of U95

O21 rebuilds the 1995 Windows game U95 as an F# open-source remake. Its author describes a black-box process based on observing the running game and reading its data files; the current engine includes rendering, menus, bonuses and some enemy behaviour but is not yet playable.

Targets: Game
Category: Independent reconstruction cases
Relationship: Independent reconstruction project
Sources reviewed: 2026-11-06
Evidence class: C2 code & docs, no demo or download

Stars: 31
Last commit: 2026-10-26
Language: F#
License (GitHub): MIT

GitHub data as of 2026-11-10

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Evidence

Observed: Code and documentation observed; no download method or demo found.
Checked: 2026-11-09

How evidence classes are assigned

Requirements & limits

Prerequisites: Original U95 resources are needed to run the game.
Prerequisites: Development builds require .NET 10 SDK or later.
Limits: The current implementation is not in a playable state.
License: MIT license, except where individual files state otherwise.

Cite

BibTeX

@misc{o21-u95-case,
  title = {{O21: a black-box remake of U95}},
  howpublished = {\url{https://github.com/ForNeVeR/O21}},
  url = {https://github.com/ForNeVeR/O21},
  urldate = {2026-11-06},
  note = {Awesome REA entry: \url{https://awesomerea.org/resources/o21-u95-case/}}
}

Plain text

O21: a black-box remake of U95. https://github.com/ForNeVeR/O21 (accessed 2026-11-06). Awesome REA entry: https://awesomerea.org/resources/o21-u95-case/

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About this entry

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Primary sources

README.md GitHub · ForNeVeR/O21 · Revision cad9084
CHANGELOG.md GitHub · ForNeVeR/O21 · Revision cad9084