Joomla and Mambo CMS have been developed by the same professionals of web design industry. So, they possess a lot of common features. For example similar code, system requirements, etc. At the same time new releases of Joomla will differ from Mambo. Having compared Joomla and Mambo CMS‘s you can notice that Joomla has more options, better security issues, regular updates, additional Built-in-Applications, etc.
While people having skills in HTML and other web scripting languages can opt for designing their own site it is not a viable choice for everyone. Some of the web designers use pre defined and readymade web templates for quick and effective site designing.