It's always been possible to use service bridges to delegate tasks between Drupal sites. Recently however a lot of new modules have been implemented for Drupal that are (going to) making this a lot easier. So much easier that I believe that Drupal service clouds, in which features are distributed over more than one specialized site, will become one of the great architecture options (together with organic groups, domain access and installation profile powered multi-site setups) to keep in mind when planning a project.
Together with the renaissance of installation profiles and Drupal distributions, this will make it more interesting to integrate a couple of distributions with a custom site than to try building all the features into 1 site. This is already happening with third party software integration projects such as the Alfresco and Apache Solr modules. A similar distributed feature architecture could however also be very interesting if implemented with a series of specialized Drupal sites.
In this post I'll talk about the pro and contra's of this approach and do a short review of the technologies that could be used to implement it.
