Professional communities in real life and in web sites are created around projects, visions and shared ideas. Usually cobwebs are developed around collaborations, solutions, people who created a sort of collective mind that globally either think over the problem to solve or over the project that has to be developed. So, they are webnets communities not only for technologies they normally use but also for their structure and how they use their own ideas in a sort of back-action, their work in the community, creating it in fact, managing it, forming intellectual and creative possibilities that act as space/time possibilities of local, territorial or traditional professional communities.
On the web, communities join together around problems to solve, such as in software sector. Problems can be completely new (for creating a non-existent software or, if it does exist, very expensive; see OpenOffice vs Microsoft Office), or attached to software operating systems or already existing procedures (usually to solve creative or technical problems). In music the rule is exactly the same: communities users of the same software, communities joined by the same musical genre or creative ones exchange among them information, techniques and musical projects.