As per the book activiti in action, I see there is a setup directory for installing activiti framework in v5.10, and there is no setup directory in v5.13.
Is it removed in latest version ? And why do we need to install it when we have eclipse plugin(activiti designer) ?
There is no setup anymore. Just deploy the activiti-explorer.war or activiti-rest.war file in a container (e.g.. tomcat) and you're good to go. Once you're familiar with those apps, you can use activiti in your project as a library (using maven, for example) to start using the API.