We have an application for sending the application specific alerts to users via email. This application is a windows service written in C# language. We use Cisco WebEx connect for internal communication in our company and we are planning to integrate our application with Cisco Webex Connect to send alerts as instant messages to the users. We are looking for any Cisco API/SDK available for this requirement.
WebEx Messenger uses standard XMPP. You could easily create a user account for a 'bot' to sign into, then program the bot to deliver IMs to other users based on external events of any sort.
A quick google search for 'XMPP bot c%' turns up many posts describing how to create simple XMPP bots that you could use as a starting point.