** use .xo format only if user requested .xo creating
** use .xo format only if user requested .xo creating
** otherwise, activities should just start by click
** otherwise, activities should just start by click
+
** activities will be represented by regular 0install feeds
+
*** more flexible dependency checking then on ASLO(only SP version), if activity requires recent gst to run, it just declare gst version(like regular 0install feeds)
+
**** variety of activity versions will be checked in runtime to detect what versions could be run on particular machine