Open-source content management systems now compete with the leading proprietary CMS packages. They generally run on Apache, itself the dominant web server, with nearly twice the market share of the leading proprietary web server, IIS from Microsoft.

Although there is often no licensing cost for an open-source CMS, the real costs of running a CMS - the physical hardware and Internet connectivity, staff training, consulting fees - can still run to hundreds of thousands of dollars for large web content sites with many content contributors and thousands of pages.

For million-dollar plus CMS installations, licensing fees may run less than one-third of the total cost. That said, for a small organization, an open-source CMS can seem almost free if existing staff use it to manage web content more productively.