An unofficial patch is a non-commercial patch for a commercial software created by a user community instead of the original developer. Similar to an ordinary patch, it alleviates bugs or shortcomings.
A common motivation for the creation of unofficial patches is missing technical support by the original software developer or provider. There are several potential reasons:
- the software product reached its defined end-of-life and/or was superseded by a successor product (planned obsolescence)
- the developer has gone out of business and is not available anymore (abandonware).
- support is economically not feasible (e.g. localization for small markets)
- a fast solution for a time critical problem (e.g. security holes) when an official one takes too long
- the official developer is unable to cope with the problems
In the computer game domain, where unofficial patches are most common, unofficial patches are also sometimes called Fan patches, especially if produced by an individual person. Combined patches, including the work of several developers and authors from the community, are also called Community Patch. They are aiming typical for critical bugs in the program flow which could lead to program crashes and technical compatibility fixes, e.g. for newer operating systems, increased display resolutions or new display formats.
As another kind of unofficial patches are fan translations of software, especially games, to local languages. Fan translations are most common for Japanese role-playing games which are often not localized for Western markets.
Another variant of unofficial patches are slipstream like patches which combine official patches together, which are only available online or as small incremental patches.
The most common case is that the source code and the original development tools are not available for the software. Therefore, the faulty software behaviour must by analyzed binary on run-time with reverse engineering and debugging. If the problem is found, a fix to the program must be applied. Sometimes only small changes in configuration files or the registry are required, sometimes binary hacks on the executable itself are required to fix bugs. If a software development kit (e.g. for modding) is available, fixes to the content can be easily produced, otherwise the community would need to create their own tools. These found fixes are typically packed to user deployable patches (e.g. with NSIS, Innosetup).
If the source code is available, support can by provided most effectively. Sometimes the source code becomes available by intendation, sometimes by leaking  or mistake like it happened for the Game engine of the Thief series. With the source code available even the support of completely different but actual platforms by Source ports becomes possible.
Reception of unofficial patches is mixed, but by large, copyright holders are ambivalent. When the software is not considered commercially viable unofficial patches are ignored by the copyright holder as it is not seen as a source of lost revenue. There have been seldom cases of cease & desist letters to unofficial patch and fan translation projects.
Source code release
Examples in video games
Examples in general software
|Adobe Acrobat||fast security fix|
|Java||fast security fix|
|Windows 98||Slipstream patch, Bug fix patch, support for harddrives > 137GB, support for XP API|
|Windows XP||Update pack|
|Internet Explorer||fast security fix|
|Nvidia nForce Chipset Device driver||Support for older Chipsets on newer Windows OSs'|
|Windows Metafile format||fast security fix|
|Windows URI problem||fast security fix|
|Mac OS 3.5||Daylight saving time patch|
- Dirscherl, Hans-Christian (2005-11-29). "Nicht tot zu kriegen: Win 98 Service Pack 2.1". PCWelt.de. Retrieved 2011-04-06.
- Cassia, Fernando (2007-03-28). "Open Source, the only weapon against "planned obsolescence"". theinquirer.net. Retrieved 2012-01-15.
- g4tv staff (2011-05-30). "The Lost History of System Shock". g4tv.com. Retrieved 2012-05-30. "Looking Glass Studios closed in 2000, a year after System Shock 2's release, and the copyright to the series went into the hands of an insurance company. That left EA with only the System Shock name, but no actual development rights."
- Naraine, Ryan (2006-01-04). "IT Security & Network Security News - Another Unofficial WMF Patch Released". eweek.com. Retrieved 2012-01-07. "Security vendor ESET, makers of the NOD32 anti-virus program, on Wednesday shipped an interim patch for the bug, almost a week before Microsoft Corp. is scheduled to release a properly tested security update."
- Espiner, Tom (2006-01-06). "Firms urged to use unauthorised Windows patch". ZDNet.co.uk. Retrieved 2012-01-29.
- CNN Staff (2006-01-03). "Huge virus threat rocks Microsoft". CNNmoney. Retrieved 2012-01-29. "Because of the severity of the threat, the SANS Institute, a computer security group, has released a patch for the vulnerability until Microsoft's fix is available next week."
- Sebayang, Andreas (2009-03-23). "Gothic 3 Community Patch soll fast alle Fehler beheben - mehr als 700 Veränderungen im letzten Community Patch" (in german). Golem.de. Retrieved 2011-04-03.
- Sebayang, Andreas (2008-05-27). "High-Res-Patch für Command & Conquer 95 - Klassiker lässt sich nun in höherer Auflösung spielen" (in german). Golem.de. Retrieved 2011-04-03.
- Löding, Torge (2003-09-09). "Infogrames toleriert Fan-Übersetzung für Master of Orion 3". heise.de. Retrieved 2011-04-03.
- Parkin, Simon (2008-12-26). "You Say Tomato: A Pro on Fan-Translating Nintendo's Mother 3". gamasutra.com. Retrieved 2011-04-03.
- Szczepaniak, John (06 2006). "Japanese ROM Translation". Retro Gamer 25: 102–105. 
- Wen, Howard (2004-06-10). "Keeping the Myths Alive" (in eng). linuxdevcenter.com. Retrieved 2012-12-22. "[...]fans of the Myth trilogy have taken this idea a step further: they have official access to the source code for the Myth games. Organized under the name MythDevelopers, this all-volunteer group of programmers, artists, and other talented people devote their time to improving and supporting further development of the Myth game series."
- Largent, Andy (2003-10-08). "Homeworld Source Code Released". www.insidemacgames.com. Retrieved 2012-11-24. "With the release of Homeworld 2 for the PC, Relic Entertainment has decided to give back to their impressive fan community by releasing the source code to the original Homeworld."
- gio (2011-03-12). "Interview with Kevin Klemmick - Lead Software Engineer for Falcon 4.0". Cleared-To-Engage. Retrieved 2012-12-18. "[C2E] In 2000 the source code of Falcon 4.0 leaked out and after that groups of volunteers were able to make fixes and enhancements that assured the longevity of this sim. Do you see the source code leak as a good or bad event? [Klemmick] "Absolutely a good event. In fact I wish I’d known who did it so I could thank them. I honestly think this should be standard procedure for companies that decide not to continue to support a code base.""
- Smith, Quintin (2010-12-14). "Dark Engine Source Code Found In A Bag". Rock, Paper, Shotgun. Retrieved 2011-04-15. "As of this weekend, Christmas has come early for the Through the Looking Glass community. A CD’s been discovered containing the source code for the Dark Engine, aka the engine used by Thief, Thief II and System Shock 2 (not to mention Irrational and Looking Glass’ cancelled cold war spy game Deep Cover)."
- Grayson, Nathan (2012-09-26). "Hooray! – System Shock 2, Thief 2 Get Usability Patches". Rock, Paper, Shotgun. Retrieved 2012-11-16. "Double Fine’s Chris Remo (via Kotaku) tweeted out word of the abruptly unearthed hunks of unofficial patching gold, pointing the way to a French forum called Ariane4ever."
- "Le Corbeau" (2012-09-25). "Thief 2 V1.19 & System Shock 2 V2.4". www.ttlg.com. Retrieved 2012-11-10. "This is an unofficial patch for Thief II: The Metal Age (T2) which updates the game from v1.18 to v1.19, providing improved support for modern hardware and correcting many known bugs."
- Boulette, Bryan (2007-12-07). "E3 - Front Mission Interview". rpgamer.com. Retrieved 2011-04-03. "[…]we told Mr. Sakamoto that a fan translation had been done some years ago for Front Mission 1, and asked how he felt about such efforts. The producer replied that he actually found them very encouraging -- it's something the developers should be doing, but because they're not, the fans are doing it instead. He stated that he'd like to be able to give something back to the fans, and would like to thank personally each of the fans that worked on the translation."
- "Chrono Trigger Retranslation". chronocompendium.com. 2009-05-09. Retrieved 2011-04-03. "As of May 9, 2009, the patch is no longer hosted due to a cease & desist letter from Square Enix."
- Adamczewski, David (2001-11-21). "Infogrames lässt Übersetzung von Civilization 3 untersagen" (in german). heise.de. Retrieved 2011-04-03.
- Bell, John (2009-10-01). "Opening the Source of Art". Technology Innovation Management Review. Retrieved 2012-12-30. "[...]that no further patches to the title would be forthcoming. The community was predictably upset. Instead of giving up on the game, users decided that if Activision wasn't going to fix the bugs, they would. They wanted to save the game by getting Activision to open the source so it could be kept alive beyond the point where Activision lost interest. With some help from members of the development team that were active on fan forums, they were eventually able to convince Activision to release Call to Power II's source code in October of 2003."
- Schramm, Peter (2010). "About MVG". madvulture.de. Retrieved 2011-04-03. "Being part of the “Community Patch Team” formed to fix the great but bug-baiten “Gothic 3″ game, Mad Vulture Games was taking care of major coordination work, 3D model fixing and lots of other work for the Gothic 3 Addon “Forsaken Gods” Enhanced Edition, also being the producing company."
- "Anachronox - inoffizieller Patch". pcgames.de. 2003-05-27. Retrieved 2011-04-03.
- "Unofficial Arcanum Patch v091225 Released". gamebanshee.com. 2009-12-27. Retrieved 2011-01-10.
- Charisius, Manuel (2010-07-20). "Chrono Trigger deutsch" (in german). manuloewe.de. Retrieved 2011-04-03.
- Smith, James E. (2010-02-22). "Command & Conquer retrospective part I - We take a look at the series that put RTS on the gaming map". www.mygaming.co.za. Retrieved 2011-04-12. "Special Operations was unique to the Nintendo 64 and Playstation versions of the game, but the maps have since been extracted and included in unofficial fan patches."
- theelderscrolls.wiwiland.net. "DaggerfallSetup". Retrieved 2011-02-25.
- Baumgärtel, Tilman (2013-11-14). "Timothy Leary, der Games-Entwickler - Wie erhält man historische Computerspiele? Das Internet-Archive streamt Dutzende Klassiker" (in german). Die Zeit. Retrieved 2013-11-14. "Beim Internet Archive ist nun nicht nur das Originalspiel [E.T. the Extra-Terrestrial] von 1982 zu finden, sondern auch eine Version, die seine schlimmsten Programmierfehler korrigiert."
- "Fixing E.T. The Extra-Terrestrial for the Atari 2600". Neocomputer. 2013-02-01. Retrieved 2013-04-16.
- Sines, Shawn (2008-01-08). "Fallout 2 Restoration Project". gamefront.com. Retrieved 2011-04-03.
- Reindl, Walter (2004-06-29). "Freelancer - Großer Community-Patch erschienen" (in german). gamestar.de. Retrieved 2011-04-03.
- Alratan (2010-11-08). "Baldur’s Gate 2: Shadows of Amn Review". manapool.co.uk. Retrieved 2011-04-10. "Many of the mods and unofficial patches improve the game immensely, and are definitely recommended."
- Bradshaw, Dave (2011-11-25). "Baldur's Gate II Fixpack". gibberlings3.net. Retrieved 2012-02-03. "The BG2 Fixpack is a WeiDU compilation of fixes for Baldur's Gate II. […] This collaborative effort, including the work of modders from several different modding communities and assistance from BG2 lead writer David Gaider, has resulted in a fixpack that currently includes all of the fixes addressed by Baldurdash (including the Game Text Update) and several hundred new bugfixes. The project is ongoing, and we're working through a substantial list of bugs culled from various sites, the old Baldurdash forums, and our own research."
- Thompson, Michael (2009-10-06). "Fan-restored KOTOR II content creates refined, expanded game KOTOR II wasn't the most complete Star Wars title ever released, due to an …". arstechnica.com. Retrieved 2013-09-05. "After years of development, the cut content has been finally restored and the most of the bugs have been fixed, thanks to a project known as known as the "Restored Content Mod."
- Grayson, Nathan (2012-08-24). "Get These: KOTOR 2 And Its Restored Content Mod". Rock, Paper, Shotgun. Retrieved 2013-09-05. " On top of that, the mod fixes “over 500″ bugs, because Obsidian, basically."
- Wilde, Tyler (2012-07-26). "Community heroes: modders debug and restore cut content in Knights of the Old Republic II". PC Gamer. Retrieved 2012-09-26.
- Tsai, Andrew (2013-01-03). "The Fixer: How To Restore Knights of the Old Republic II". Rock Paper Shotgun. Retrieved 2013-01-28.
- "Legacy of Kain: Soul Reaver - XP-Patch". pcgames.de. 2004-02-12. Retrieved 2011-07-17.
- Raul, Cuban (2009-11-29). "Blood Omen: Legacy of Kain 2000/XP Update v2.0". comcast.net. Retrieved 2011-07-17.
- wrace (2010-12-03). "Bink-support for BO1 (Video-Patch)". nosgothica.org. Retrieved 2011-07-17. "[…]now you can play in BO1 under Windows-7 without any problems with video."
- Gantner, Michael (2010-12-23). "Lucasarts-Patches". la-patches.gandimann.de. Retrieved 2011-05-28.
- Wiesner, Thorsten (2003-09-10). "Deutsche Fan-Übersetzung zu Master of Orion 3 ist fertig" (in german). golem.de. Retrieved 2011-04-03.
- Sharkey, Mike (2012-03-14). "Unofficial Skyrim Patch Fixes Myriad Skyrim Bugs - Fan created uber patch designed to fix Skyrim's many problems.". gamespy.com. Retrieved 2012-12-22.
- Quarn and Kivan (2013-08-20). "Unofficial Skyrim Patch Version: 1.3.3c". nexumods.com. Retrieved 2013-10-03. "[...]the goal of the Unofficial Skyrim Patch (aka USKP) is to eventually fix every bug with Skyrim not officially resolved by the developers [...]Hundreds of gameplay, quest, NPC, object, item, text and placement bugs fixed already"
- "Skyrim - Director's Cut" (in german). scharesoft.de. Retrieved 2012-12-22. "Die Erweiterung Skyrim - Director's Cut hat es sich zum Ziel gemacht, die deutsche Version von The Elder Scrolls V: Skyrim so gut es geht zu verbessern. Vorrangig geht es darum, fehlende Übersetzungen nachzuholen und Texte und Begriffe so anzupassen, dass sie auch zu den vorherigen Teilen der Reihe passen. Mit dem beiliegenden inoffiziellen Skyrim-Patch werden zudem eine Vielzahl Fehler des eigentlichen Spiels, die die offiziellen Patches noch nicht korrigiert haben, behoben. Mit der Erweiterung könnt ihr außerdem alle englischsprachigen Texturen nun in deutscher Sprache vorfinden."
- yerkyerk (2009-06-03). "Titan Quest bugfix patch 1.17a". titanquest.net. Retrieved 2012-07-27.
- Voyager (2007-04-08). "Ultima The Reconstruction - Fanpatches". reconstruction.voyd.net. Retrieved 2011-05-28.
- Neuhaus, Hanno (2010-11-12). "Vampire 2: Bloodlines - Community-Patch 7.2 zum Download". gamestar.de. Retrieved 2011-04-03.
- Alratan (2010-12-06). "Vampire: The Masquerade – Bloodlines Review". manapool.co.uk. Retrieved 2011-04-10. "There are two rival patches to choose from, the True Patch and the Unofficial Patch, each with different design philosophies. Normally this would not be worth mentioning, except that the basic game is so full of bugs, that you simply must use one of the two to play the game without killing yourself."
- Meer, Alec (2011-07-15). "Undying: Vampire Bloodlines Patched Anew". rockpapershotgun.com. Retrieved 2011-08-02. "Bloodlines […] was essentially abandoned by its publisher after its developer closed a few months after release, but the fans have just kept on going, fixing things, improving things, digging up locked away extra content […]"
- Haas, Pete (2009-07-03). "Vampire: The Masquerade - Bloodlines Still Getting Patches". GAMING BLEND. Retrieved 2012-01-07.
- Leyden, John (2009-02-24). "Unofficial patch plugs 0-day Adobe security vuln. - Mind the gap". The Register. Retrieved 2013-07-09. "Updated Security researchers have developed an unofficial patch for a zero-day Adobe Acrobat and Reader vulnerability that's become the subject of hacker attacks. Adobe acknowledged the vulnerability last week but said an official patch wouldn't be available until 11 March."
- Kaplan, Dan (2012-08-27). "New Java exploit on the loose, unofficial patch may help". scmagazine.com. Retrieved 2013-07-09.
- Kuhbach, Sebastian (2005-08-04). "Inoffizielles Win98 SE Service Pack - neue Version". winfuture.de. Retrieved 2011-04-06.
- "48-bit LBA Tools & Drivers". fryeware.com. 2005. Retrieved 2011-04-06. "Win98: Enable 48-bit LBA patch for Windows 98 posted on MSFN.ORG - Implements 48-bit LBA support into Windows 98's default IDE driver to support hard drives larger than 137GB."
- Turner, Neil (2010-05-17). "Resurrecting a dead OS with KernelEx". Neil Turner's blog. Retrieved 2011-04-06.
- KernelEx by xeno86 Sourceforge.net
- Tiensivu, Aaron (2009-04-09). "KernelEx - run XP/2K apps on Win98 and WinME". Aaron Tiensivu's Blog. tiensivu.com. Retrieved 2011-04-06. "This is a fascinating project from a technical standpoint. They are implementing missing API calls used by newer applications that are missing from Windows 98 and Windows ME."
- Vahldiek, Axel (2007-03-20). "Microsoft geht gegen unautorisierte Update-Packs vor". heise online. Retrieved 2011-04-06.
- "Inoffizielle Patch-Pakete für Windows 2000 und XP (Update)" (in german). Golem.de. 2005-11-10. Retrieved 2011-04-06.
- "Another unofficial IE patch offered to counter critical flaw". Computer Weekly. 2006-03-30. Retrieved 2013-07-09. "Another unofficial patch has been released to counter a critical flaw in Microsoft’s Internet Explorer browser."
- Abazovic, Fuad (2006-11-17). "Nvidia cuts Vista support for Nforce 2 chipset - Fare thee well, old friend". www.theinquirer.net. Retrieved 2011-05-28.
- Fernando (2011-02-07). "XP: Optimized nForce Driver Packs". Retrieved 2011-05-28. "Many users with an nForce chipset mainboard, who are running or going to install Windows XP (32/64bit), are searching for actual nForce chipset drivers, which are suitable for their special chipset and will give them the best possible performance and stability of their system. NVIDIA itself doesn't offer them."
- AdvModDev (2008-01-13). "nForce 123/WinXP Chipset Drivers and Remixes". Retrieved 2011-05-28.
- Barwise, Mike (2007-10-16). "Unofficial patch for Windows URI problem". The H Security. Retrieved 2012-01-29.
- Kennedy, Erik (2007-01-28). "An unofficial Daylight Saving Time fix for Mac OS X 10.3". Ars Technica. Retrieved 2012-01-29.