Apache Subversion facts for kids
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| Original author(s) | CollabNet |
|---|---|
| Developer(s) | Apache Software Foundation |
| Initial release | 20 October 2000 |
| Written in | C |
| Operating system | |
| Type | Revision control |
| License | Apache-2.0 |
Apache Subversion, often called SVN, is a special tool that helps people manage and track changes to files. Think of it like a time machine for your projects. Software developers use it to keep a history of their work, like source code, websites, and documents.
Imagine you're writing a big school report or creating a video game. You might save many different versions like "report_v1.doc", "report_v2.doc", and "report_final_final.doc". Subversion does this automatically and in a much more organized way. It lets you go back to any older version of a file and see exactly what was changed.
Subversion is open source, which means anyone can use it for free. It was created to be a better version of an older system called Concurrent Versions System (CVS). Many large projects, like the Apache Software Foundation and FreeBSD, have used Subversion to organize their work.
Contents
History of Subversion
In the year 2000, a company called CollabNet started the Subversion project. They wanted to create a new version control system that worked like the popular CVS but fixed many of its problems.
By 2001, Subversion was already good enough to manage its own source code. The first official version, 1.0, was released in February 2004.
In 2009, Subversion joined the Apache Software Foundation, a famous non-profit organization that supports many open-source projects. It officially became a top-level Apache project in February 2010. This meant it was recognized as a major, well-supported piece of software.
What Can Subversion Do?
Subversion has many cool features that make it useful for developers working alone or in big teams.
Saving Changes Safely
When you save your changes in Subversion, this is called a "commit." Subversion makes sure that your entire set of changes is saved all at once. If your computer crashes or the internet disconnects in the middle of a save, the project won't get corrupted. The save either works completely or not at all, keeping your project safe.
Tracking Files and Folders
Subversion doesn't just track changes to files; it also tracks entire folders. You can move or rename files and folders, and Subversion will remember their entire history. This is very helpful for keeping a project organized over time.
Working with Any File Type
Subversion can handle any type of file, from simple text documents to large images and videos. It is smart about how it stores changes to large files, so it doesn't take up too much disk space.
Branching and Tagging
One of the most powerful features of Subversion is "branching." A branch is like making a copy of your project to work on a new idea. For example, if you want to add a new feature to your game, you can create a branch. This lets you experiment freely without affecting the main, stable version of your project.
If your new feature works well, you can "merge" it back into the main project.
"Tagging" is like putting a bookmark on a specific version of your project. For example, when you release version 1.0 of your software, you can create a tag. This makes it easy to find and go back to that exact version in the future.
How Subversion Stores Files
A project managed by Subversion is called a "repository." This is the central place where all the files and their complete history are stored. Subversion has had a few different ways of storing this data over the years.
- FSFS: This is the modern and most common way Subversion stores its data. It was introduced in 2004 and is known for being fast and reliable. It stores the project files in a way that is similar to how your computer's normal file system works.
- Berkeley DB: This was the original storage system used by Subversion. It worked well but could sometimes get locked up if a program crashed. It is now considered outdated and is no longer recommended for new projects.
How to Access a Subversion Project
There are a few different ways for a user to connect to a Subversion repository to get files or save changes.
- On the same computer: If the repository is on your own computer, you can access it directly.
- Over the internet: You can connect to a Subversion server using a web browser link (starting with http:// or https://).
- Using a special protocol: Subversion also has its own special connection method, which uses a link starting with svn://.
Limitations of Subversion
While Subversion is very useful, it has some limitations.
One issue is that it sometimes gets confused when a file is renamed or moved, especially if other people are making changes to the same file in a different branch. Newer versions of Subversion have improved this, but it can still be tricky.
Also, Subversion is a centralized system. This means there is one main server that holds the entire project history. Everyone connects to this central server to get updates or save their work. Some developers prefer decentralized systems, like Git, where everyone has a full copy of the project's history on their own computer.
Images for kids
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A diagram showing how Subversion can track different versions (revisions) of files and folders.
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This shows how a project can have a main "trunk," as well as "branches" for new development and "tags" to mark important versions.
See also
- List of version-control software
- Comparison of version-control software
- Comparison of Subversion clients
- TortoiseSVN
