There are literally thousands of Content Management System C(MS) technologies on the market. Some are free, some you have to pay for. Some are new kids on the block, others have been around for years.
To review up to date statistics on the popularity of the Open Source CMS's available, visit builtwith.com, for more information.
Wordpress is clearly the most popular CMS on the planet. It tends to dominate at the low-medium end of town in terms of size and sophistication, whereas Drupal tends to dominate at the medium-large end of town, especially corporates and governments.
Wordpress is more user-friendly than Drupal to administer, and great for getting new, relatively simple websites up and running quickly and easily. Drupal is a more "fine grain" product. We like to say that Drupal is to Wordpress, as Lego is to Transformers, i.e. Drupal is ultimately more flexible because it's made up of much smaller component parts. It's a double-edged sword though, because it takes experienced hands to put Drupal together in optimal configurations.
Drupalise is the arm of Itomic that specialises - of course - in Drupal. Itomic is also expert with Wordpress. We like to keep our bases covered and our clients serviced with the most appropriate solutions.