As a webmaster do we need a CMS(Content Management System) to start a site or go for custom portal development? When one enters the Internet world this is the first technical question that always comes in the mind of every new webmaster after you have grabbed the domain name and the server space.
I've compiled some advantages and disadvantages of using CMS.
Advantages of CMS:

1. CMSs are well written software and tested by a large community of users.
   So you'll not find common coding bugs and errors.
   
2. Most of the CMS are easy to install.
   
3. Your site can be up and running quickly and you don't need to spend lot of time.
   
4. Most of the CMS are free nowadays.
   Even the paid ones cost few bucks only.
   
5. You can get any free technical support from the developers community.
   
6. CMS softwares can be migrated in different servers and most of them can work with any database.
   

Disadvantages of CMS:

1. For a simple and small site CMS can be very heavy.
   
2. To add or configure any existing feature you need to understand the codebase of CMS if they don't have the plugin for this.
   
3. Different pages of portal can't have different theme or CSS when you use CMS.
   
4. If a CMS is not avaialble to a different technology then migrating a site is rellay impossible and cumbersome work.
   
5. Hiring a developer for configuring a CMS costs more as most of the popular CMS are heavy in size.
   

Example of some popular free CMS are:

• Tinyportal-SMF (This requires SMF forum to be installed then tinyportal to be installed as a plugin.
  Here is a link to one popular community site for Programmers, developers, students and webmaster containing IT discussion forum and large collection of java/php/Ajax/javascript/Linux tips and articles which is developed using CMS (Tinyportal): http://www.
  techcubetalk.
  com)
• Joomla (Very popular CMS and lots of sites are running Joomla)
• CMS Made simple
• Wordpress (Though this is a blog publishing software but it can be used as a CMS.
  Example site is www.
  technotalks.
  com)