Abstract
A virtual community is a composition of heterogeneous and independently designed subsystems, sharing services, resources, information, and knowledge to achieve a common goal. The concept of virtual community is very general and open to a number of interpretations (Ao & Misky, 2003; Sadighi & Sergot, 2002). Members belonging to a virtual community, indeed, may be represented by human beings, if the virtual community is a collection of people sharing common interests and ideas, or roles, programs or software/hardware modules, if the community is an automated system for sharing computing resources (Welch & Foster, 2002). The resource shared among a community may be computational resources as well as documents, information, or data. Whichever is the community-specific goal and features, assuming a community composed by interacting entities, several open issues need to be addressed, for instance, how to manage access policies to coordinate resource sharing, how to establish a community, how to oblige member communities to respect community policies, and so on. In the real world, to set up an organization it is necessary to perform some fundamental steps. First, the founder members have to draft a constitution, specifying the object and purpose of the organization, the rules, the kind of services and information provided. The constitution may be directly released to members or officially published in a registry’s Office. Furthermore, constitution must establish rules and responsibilities that each member has to follow. To join the community, a subject commonly has to apply for membership. The application consists of a procedure, where the applicant communicates his/her personal data, subscribes to the regulation of the community, and informs whether he/she has something to share, and which are the conditions under which he/she will release his/her services. Similarly, in order to start up a virtual community, it is necessary to define participant roles and resources to be shared, as well as a regulatory system composed of community laws and/or local laws defined by single members.