(added into main WF FAQ)

From workflow, the action "Webhook" allows you to trigger a webhook URL for a third party system. 

You can specify the URL to trigger, and the raw payload data. 

You can send information regarding the triggering record in the payload (or URL) using standard email merge variables. 

An example of this, is on change of a ticket status, send a message about the ticket to a channel in your Instant Messaging tool