Joomla! is very popular open source software project with wide community of users. Thanks to its licensing conditions (GPL), you do not need to pay for the software itself, which may reduce costs for your website construction. Because the open source nature, it is also possible to customize the code to best suit your needs and requirements. (Please note this may not apply to additional 3rd party components.)
The great advantage is also rich choice from all kinds of plugins that may be further incorporated into the site and again speed-up and reduce costs of the implementation.
Top reasons for using Joomla.
Joomla! Feature List:-