A changelog (also spelled change log) is a log or record of all notable changes made to a project. The project is often a
website
A website (also written as a web site) is any web page whose content is identified by a common domain name and is published on at least one web server. Websites are typically dedicated to a particular topic or purpose, such as news, educatio ...
or software project, and the changelog usually includes records of changes such as bug fixes, new features, etc. Some
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...
projects include a changelog as one of the top-level files in their distribution.
A changelog has historically included all changes made to a project. An alternative approach has been suggested that the log should instead contain "a curated, chronologically ordered list of notable changes for each version of a project" and should not be a "dump" of a git log "because this helps nobody".
Although the
GNU (
Automake) canonical naming convention for the file is ''ChangeLog'', it is sometimes alternatively named as ''CHANGES'' or ''HISTORY'' (''NEWS'' is usually a different file reflecting changes between releases, not between the commits). Another convention is to call it a ''CHANGELOG''.
Some
project maintainer
In free and open source software and inner source software, a Computer software, software maintainer or package maintainer is usually one or more people who build source code into a Executable, binary Software package (installation), package for So ...
s will append a ''.txt'' suffix to the file name if the changelog is
plain text
In computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects ( floating-point numbers, images, etc.). It may also include a lim ...
, a ''.md'' suffix if it is in
Markdown
Markdown is a lightweight markup language for creating formatted text using a plain-text editor. John Gruber created Markdown in 2004 as an easy-to-read markup language. Markdown is widely used for blogging and instant messaging, and also used ...
, or a ''.rst'' suffix if it is in
reStructuredText.
Some
revision control
Version control (also known as revision control, source control, and source code management) is the software engineering practice of controlling, organizing, and tracking different versions in history of computer files; primarily source code ...
systems are able to generate the relevant information for a changelog, if the goal is to include all changes.
Format
Changelog files are organized by paragraphs, which define a unique change within a function or file.
The
GNU Coding standards recommend the following format:
Between the date and the name, and again between the name and the email address, there are two spaces each. It is common to enclose the email address in < and >. The
Emacs editor creates such entries when creating additional changelog entries.
Changelogs in wikis
Most
wiki
A wiki ( ) is a form of hypertext publication on the internet which is collaboratively edited and managed by its audience directly through a web browser. A typical wiki contains multiple pages that can either be edited by the public or l ...
software includes ''changelogs'' as a fundamental feature (often called ''history'' in this context). For example, the "View history" link at the top
[ Help:Page_history.] of a
Wikipedia
Wikipedia is a free content, free Online content, online encyclopedia that is written and maintained by a community of volunteers, known as Wikipedians, through open collaboration and the wiki software MediaWiki. Founded by Jimmy Wales and La ...
entry links to that page's changelog. This feature is vital for complying with the attribution requirements of some copyright licenses.
Product changelogs
A product changelog can keep customers in the loop about what's new. It helps to announce new features, latest releases, and relevant news directly in-app.
See also
Notes
External links
GNU Coding Standards: Change LogsKeep a CHANGELOGChecklist for creating a changelog{{Wiktionary, changelog
Computer files
Free software culture and documents
Technical communication