Changes

Sometimes a full system emulator is overkill. This is especially true when a developer only wants to get one game (or a number of games that use the same engine) working. In that case, reimplementing re-implementing that game alone would save more time than implementing the platform it runs on. These kinds of projects are common when abandonware has large communities; when the original developer has disbanded and can no longer support or update it, an effort is then made to get it running natively on newer versions of-- and/or entirely different-- operating systems and platforms.

* When the developer only has a binary to work with (and not the [[source code]]), they recreate the engine rather than port it, hence the term '''[[wikipedia:Game engine recreation|game engine recreations]]''' (or alternatively '''game engine re-implementations'''). How the developers go about this process depends on their philosophy; they may opt to decompile de-compile the original executable and have their own program rely on the original until all of its functions have been remade, at which point the original binary is no longer needed. Alternatively, they can be remade based on a clean room design, in which the project implements the abstract features without having to disassemble the original, going by how components are expected to be used rather than how the game uses them. Some engines come about simply because they were inspired by the original game, and the programmer felt confident enough that no reverse engineering was necessary to make an engine that does the same thing.

Some projects are implemented in ways that the original developer did not intend; for example, for a platform other than which publishers marketed it for. And they're not just limited to game engines either; [https://webamp.org/ Webamp] is a JavaScript application that reimplements re-implements Winamp in the web browser. These projects are almost always open-source , which also allows new programmers to fix bugs that could have been difficult to track down during development (alternatively, the bugs may be emulated to allow old mods to continue to safely exploit them). When most of the effort is on programming, the project will usually require the original game's assets (such as files in the installation directory or ROMs) until those ever get remade. This lets the developers claim they aren't infringing the game's copyrights since the player must obtain the original to use it; if the game is still being sold, this could allow the publisher to even earn revenue from the project. This aspect is debatable however, as some source code recreations did result in cease-and-desist letters and even lawsuits from companies such as in the case of [[re3|re3 ]] and reVC for the 3D-era ''Grand Theft Auto'' games, with Take-Two Interactive alleging that the source ports were made to facilitate piracy and that "the work is not licensed in any way"; some have speculated that the suit among others was to keep fan-made mods from getting in the way of their much-maligned ''Definitive Edition'' remasters.

On Linux downloading and using game engines is easy with [https://github.com/luxtorpeda-dev/luxtorpeda Luxtorpeda] - a Steam Play compatibility tool (like [[Proton]]) that allows you to run games from Steam using various different game engines and reimplementationsre-implementations. Alternatively some package managers/app stores, such as [https://flathub.org/ flatpak] and [https://snapcraft.io/ snap] include source ports.

| align="left" |{{Icon|Windows|Linux|macOS|Android|iOS}}{{Icon|LinuxARM|3DS|Switch|GBA|Xbox}}

|{{~✗}}

| align="left" |{{Icon|Windows|Linux|macOS|FreeBSD|AmigaAmigaOS|Switch}}|[https://github.com/dhewm/dhewm3/releases git]<br/>[http://hunoppc.amiga-projects.net/content/dhewm3-amigaos4 dhewm3-amigaos4]

| align="left" |{{Icon|Windows|Linux|macOS|AmigaAmigaOS}}

|[https://sourceforge.net/projects/openmohaa/SourceForge]

|[https://lerppu.net/wannabethesis/pcexhumed/20230620-13623]

|[https://wiibrew.org/wiki/QRevPAK Quake Rev PAK]<ref group="N">Quake Rev PAK (or QRevPack for short) is a collection of game engines of the ''Quake'' series that merges [https://wiibrew.org/wiki/Q1Rev Q1Rev] (''Quake 1''), [https://wiibrew.org/wiki/Q2Rev Q2Rev] (''Quake 2''), [https://wiibrew.org/wiki/Q2CTFRev Q2CTFRev] (ThreeWave Capture the Flag mod for ''Quake II''), and [https://wiibrew.org/wiki/QWRev QWRev] (''QuakeWorld'') in one. All by the same developer Izhido.</ref>

| align="left" |[[File:N64_logo.png{{Icon|25px]]N64}}

|{{✓}}<abbr title="Original project taken down due to Nintendo's tools used for building the game for Nintendo 64, this one aiming to remove the requirement on proprietary code, so Nintendo will ... :)">*</abbr>

|FNaF 1 3DS -old/obsolete-<br />[https://www.gamebrew.org/wiki/Five_Nights_at_Freddys_1_3DS FNaF 1 3DS -remastered-]<ref group="N" name="FNaF3DS">Five Nights at Freddy's 1 3DS -remastered- is an updated version of [https://gamejolt.com/games/fnaf13ds/507412 Five Nights at Freddy 1's 3DS] by the same developer FreDev, also known as BumboDEV and BaseDEV. The developer also attempted Nintendo 3DS ports of ''Five Nights at Freddy's 2'', ''3'', and ''4'' but development stopped after the developer lost the source code for ''Five Nights at Freddy's 2'' and would have to reverse engineer it again.^{[[https://gamejolt.com/p/i-have-decided-to-release-the-latest-version-i-have-available-for-f-ctwvb9xilost the source code]} for ''Five Nights at Freddy's 2'' and would have to reverse engineer it again. Those ports were only in a state of demonstration and were not fully playable, having incomplete A.I., gameplay, and missing screens. Download links to the latest version of these 3DS ports and the PS Vita port can be found on the [https://discord.gg/w7WcSGt old Discord server].</ref>

|{{✗}}<supref group="N">Cave Story Engine 2's[https://github.com/gameblabla/CSE2/blob/rs97/LICENCE.txtlicence]</supref>

|{{✗✓}}<ref group="N">no active development on GitHub but issues section has had active discussion, development unlikely to revive though. </ref>

|{{✗✓}}

| align="left" |{{Icon|Windows|Linux|GameCube|BeOS|AmigaAmigaOS|GP32}}

|[http://dunedynasty.sourceforge.net1.5]

| rowspan="67" |Real-time strategy

|[https://dune2themaker.fundynamic.com0.7.0]

|[http://dunelegacy.sourceforge.net/website/index.html27.12.2022]

| align="left" |{{Icon|Windows|Linux|macOS|FreeBSD}}

|{{✗✓}}

|[https://www.moddb.com/mods/undertale-mobile-modModDB page]

|[[iarchivehttps://archive.org/details/psp-minecraft.-7z|3.0.0]]

|[https://www.openttd.org/en OpenTTD]

|[httphttps://web.archive.org/web/20181127195119/https://www.civone.org / CivOne]

|{{~}} <small>(WIP)</small> <ref group="N">No longer needed as the game has been released on PC.</ref>