Of  the various Open Source CMS software, WordPress, Joomla and Drupal are the dominant open source brands in the market. Our examination of the open source CMS market is by attempting to measure the relative rates of adoption of the systems. We have measured the relative rate of adoption with the help of three parameters – Download, Development Services and Books in Prints.

1. Download

WordPress tops the download rate while Joomla! stands the second. However download rates are not constant over time, a new release will generate a large amount of excitement and an accelerated download rate for the period immediately following the release.

2.  Development Services

Joomla! stands first followed by WordPress in terms of development services offered by third parties. This statistics is based on Elance and Guru that provides a mechanism for buyers to locate freelance professionals. The site is focused on web, programming, writing and related professions.

3. Books in Prints

A visit to Amazon to findout who has the largest number of books in print and which CMS has been the subject of publishing activity show that Joomla!, Drupal and WordPress are the top three.

WordPress

WordPress is widely thought of as a blogging
platform, but the reality is that the WordPress CMS product is powerful and flexible enough to be used as a more typical web CMS and increasingly is so used. WordPress is a state-of-the-art publishing platform with a focus on aesthetics, web standards, and usability.

Joomla

Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful web based online applications. Its most important features like ease-of-use and extensibility, have made Joomla the most popular Web site software available. Best of all, Joomla is an open source solution that is freely available to everyone.

Drupal

Drupal is a free software package that allows an individual or a community of users to easily publish, manage and organize a wide variety of content on a website. Tens of thousands of people and organizations are using Drupal to power scores of different web sites, including Community web portals, Discussion sites, Corporate web sites, Intranet applications, Personal web sites or blogs, Aficionado sites, E-commerce applications, Resource directories, Social Networking sites

List of other  prominent open source content management systems are:

1. b2evolution

2. CMSMadeSimple

3. e107

4. Elgg

5. eZ Publish

6. Mambo

7. MediaWiki

8. MODx

9. php-Nuke

10. phpWebSite

11. Pligg

12. Plone

13. SPIP

14. TikiWiki

15. Typo3

16. Xoops

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