An unofficial patch is a non-commercial patch for a piece of software, typically commercial, created by a user community instead of the original developer. Similar to an ordinary patch, it alleviates bugs or shortcomings. Unofficial patches do not usually change the intended usage of the software, in contrast to other third-party software adaptions such as mods or cracks.
Contents
Unofficial patches as user-created content which is typically distributed over the web can be seen as part of the Web 2.0 and the remix culture.
Motivation
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:
Types
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.
While unofficial patches are most common for the PC platform, they are also existing for console games e.g. in context of the emulation community.
Translations
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.
Methods
The most common case is that the source code and the original development tools are not available for the software. Therefore, the faulty software's binary must be analyzed at run time by 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, such as what happened with the game engine of the Thief series. Sometimes fans even completely reverse-engineer source code from the original program binary. With the source code available even the support of completely different but recent platforms with source ports becomes possible.
Law
While court cases directly involving unofficial patches are not existing, there were similar cases in court. The case of Galoob v. Nintendo found that it was not copyright infringement by a user to apply an unauthorized patch to a system (while the scope was very specific to the Game Genie). On the other hand, the case Micro Star v. FormGen Inc. found that user generated maps were derivative works of the original game. In Sega v. Accolade, the 9th Circuit held that making copies in the course of reverse engineering is a fair use, when it is the only way to get access to the "ideas and functional elements" in the copyrighted code, and when "there is a legitimate reason for seeking such access". According to Copyright law of the United States 17 U.S. Code ยง 117, the owner of a copy of a program can modify it as necessary for "Maintenance or Repair", without permission from the copyright holder; an argumentation also raised by Daniel J. Bernstein professor at the University of Illinois at Chicago. Similar user rights are given also according to European copyright laws. The question if and which copyright holder unauthorized changes of lawfully obtained software are fair and beneficial, is a long-standing debate among academic scholars.
Reception
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.
Sometimes the copyright holder actively support the patching and fixing efforts of a software community, sometimes even by releasing the source code under a software license which allows the software community the continued software support by themselves. Examples for such software are in the List of commercial video games with later released source code.
The free and open source software movement was founded in the 1980s to solve the underlying problem of unofficial patches, the limited possibility for user self-support in binary only distributed software due to missing source code. Free and open source software demands from distributed software the availability of source code, which prevents the technical problems and legal uncertainties of binary only user patching of proprietary software.