Subversion (http://subversion.tigris.org/) is a version control system released under an Apache/BSD-style open-source license.
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What is version control?
Version control, also referred to as revision control, source control, or source code management (SCM), is the management of multiple versions of a single item or collection thereof. Commonly used in documentation, engineering, and software development processes, particularly where a team of people are involved, it enables the tracking and retrieval of changes made to an item. Each revision is assigned a (sequential) number and normally associated with the person who makes the change. In its simplest form, each time a document is issued it is assigned the next number in the sequence starting at 1. At a future date an individual could obtain copies of the current and original documents and compare the differences between the two.
Version control systems for the purpose of software development manage all the details of this process...