The http:// access schema

One of the most appealing features of Subversion is its integration with the popular Web server Apache Httpd. This integration provides several benefits. First, Apache Httpd by default runs on ports 80 and 443 and most firewalls allow them and opening another port for Subversion is not needed. The HTTP infrastructure is also widely deployed so most of it can be reused for Subversion, for example Basic or Digest Authentication, https, storing the user credentials in an LDAP server.

When a repository is accessed through Apache, Subversion clients communicate with the server using HTTP request. Two standards that extends the original HTTP specification (RFC 2616) are employed for this communication - WebDAV (RFC 2518) and Delta V (RFC 3253).

WebDAV stands for Web-based Distributed Authoring Versioning. It defines methods for creating and deleting files and directories on the Web server. Versioning turned out to be complicated so Delta V initiated was started address the issue.

Subversion provides full WebDAV functionality and a strict subset of Delta V functionality.