Multiple instances with same code, different database

[skreutzer]

Software should support multiple instances using the same code on the webspace. If several instances are needed, it should not be required to copy the very same code, too. At the same time, every instance should use its own database_connect.inc.php (different database or same database with prefix for table names, check for conflicts) and $/web/notes_files/ directory. Just as with the language switcher, there could be a (implicit?) instance switcher (which should invalidate parts of the session).