What is a Content Management System?
A web CMS is a tool to help develop and maintain a website. They are designed to allow less IT literate people to maintain the site, and for non HTML experts to design the site. There are proprietary and open source systems. Proprietary systems cost from a few thousand to tens of thousands of pounds, and are typically sold by design or IT companies or by specialists as a software package. It is simply not sense to invest in a website and NOT use a Content Management System these days. It is also important that you invest in a proper CMS.

Why do I need a “proper” CMS?
Many proprietary CMS systems are developed by design or IT companies.
Did you know that in the UK, the average life of a software house is 3 (yes THREE) years. They go bust every year, leaving tens, hundreds or even thousands of clients in trouble. In this case you LOSE everything (your site, the software , your whole investment) and have no choice but to start again. 
Alternatively, Packaged CMS systems are expensive - from several thousand pounds up to tens of thousands.
Proper CMS systems include all sorts of features that are not in many simple proprietary systems. This is usually because either the developer is aiming at a very specific market , is trying to keep the cost down or simply has no strategy.
You do not know what features will be required in the life of your website – no proprietary system can keep up with technology and be cost effective.

What can I do?
You must choose –
EITHER pay for your security by choosing a specialist CMS package from a reputable and stable CMS vendor (and pay thousands) OR find a viable OpenSource alternative.

We use Joomla  – which is Open Source, FREE and proven – with over 250,000 installations including IHOP, MTV and Harvard University.
It has loads of standard features, and if you want to do anything outwith the standard, there are hundreds of free extensions , add-ons etc to cover almost ANY requirement.
For more information on CMS go to http://en.wikipedia.org/wiki/Web_Content_Management_System
For Joomla information go to www.joomla.org and for the extension library go to http://extensions.joomla.org/