A system and method for delivering text, media, and inline interactive data (called message content) encapsulated in a message-based conversation has been devised. Content of multiple types are rendered and manipulated using interactive program code objects, downloaded when first needed from a repository, present on the message device. Inline interactive data can be shared and manipulated by participants in a message conversation as part of and in context with the ongoing conversation. Sharing and data integrity of the inline interactive data as well as conversation participant authentication, privileges and conversation security is managed by a central message server.