There is no limit on the number of portlets, that can exist in a single portlet application WAR file. If there is a limitation you have to look into the portal server provider documentation e.g. websphere portal or weblogic portal etc
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com
subject: In a single portlet application how many portlets i can create ?