Celoxis provides a powerful way to trigger your processes by external users (without Celoxis logins) or by other applications.
Direct Interface
This helps configure your processes so that they can be initiated by a simple email. Say for example you have a Help Desk process that you wish to be triggered by a person sending mail to a specific email address. Celoxis will generate an email address to be used. A mail sent in a specific format to that email address will trigger off the process.
Indirect Interface
If you have an existing system which you integrate into one of your processes, you can use the Indirect interface to do that. Alternately you can also design a new application that triggers off a process in Celoxis. For example, you can create a web form which accepts certain information and sends off a mail which triggers the 'New Project Request' process.