software development Software development is the process of designing and Implementation, implementing a software solution to Computer user satisfaction, satisfy a User (computing), user. The process is more encompassing than Computer programming, programming, wri ...

, when software has been forked or uses a chain of

libraries A library is a collection of Book, books, and possibly other Document, materials and Media (communication), media, that is accessible for use by its members and members of allied institutions. Libraries provide physical (hard copies) or electron ...

/ dependencies, upstream refers to an issue that occurs in software related to the chain. It is the direction that is toward the original authors or maintainers of

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

. It is usually used in the context of a version, a bug, or a patch. Upstream development allows other distributions to benefit from it when they pick up the future release or merge recent (or all) upstream patches. Likewise, the original authors (maintaining upstream) can benefit from contributions that originate from custom distributions, if their users send patches upstream. The term also pertains to bugs; responsibility for a bug is said to lie upstream when it is not caused through the distribution's

porting In software engineering, porting is the process of adapting software for the purpose of achieving some form of execution in a computing environment that is different from the one that a given program (meant for such execution) was originally desig ...

, non-upstream modification or integration efforts.

Examples

* A patch ''sent upstream'' is offered to the original authors or maintainers of the software. If accepted, the authors or maintainers will include the patch in their software, either immediately or in a future

release Release may refer to: * Art release, the public distribution of an artistic production, such as a film, album, or song * Legal release, a legal instrument * News release, a communication directed at the news media * Release (ISUP), a code to i ...

. If rejected, the person who submitted the patch will have to maintain his or her own

distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...

of the author's software. * Upstream repository or

source code In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only ...

distribution ''version'', which can either be a version-tagged release for which the source code has specifically been packaged, a specific commit, or master (jargon for latest commit). Where custom distributions (such as forks) may have missed out on bugfixes and improvements (maturing of the project tied to the original authors, upstream) as a result of not merging (all) upstream patches. In such cases, the custom distribution may even have been adapted to suit the specific needs and requirements of those using or maintaining it. This is also often seen with dependencies (vendor packages), where the taker just settles with a base version once and tends to stick with it, over time accumulating so many (arbitrary) modifications or non-standard uses in their environment that merging the latest upstream patches into their custom distribution won't be possible without major additional work for patch and feature compatibility, and avoiding duplicate patches of bugs that they resolved by themselves (and in their own way) while upstream also has a patch for it. A lot of custom distribution users would still cherry-pick and merge critical upstream patches (such as

security vulnerability Vulnerabilities are flaws or weaknesses in a system's design, implementation, or management that can be exploited by a malicious actor to compromise its security. Despite a system administrator's best efforts to achieve complete correctness, vir ...

related).

References

Computing terminology Software project management {{Compu-prog-stub

Examples

See also

References