A spell being cast after a stance.
A skill being interrupted.
The skill monitor is an element of the Interface that allows you to view the skills used by another player, NPC or monster. Any creature highlighted by the targeting system is subject to the skill monitor. It displays the icon of the skill, as well as the full name of the skill, and if the target is casting/using any skills, you can view a bar filling to show how much longer before the skill is executed. The full description of the skill can be displayed as a tool-tip by moving the mouse over the skill icon.
The skill monitor is particularly useful to use in conjunction with interrupt skills, and can also be used to identify what individual characters are doing which may help in picking out the best target.
Skills with no activation time are displayed at a lower level of the Skill Monitor behind regular skills.
The casting bar shows a green color when casting, a yellow color when completed and a purple color when interrupted.