[April 2011] According to RIA Stats (
http://riastats.com), 97% of total internet-connected machines run Adobe Flash, 74% run Sun Java, and 73% run Microsoft Silverlight. One can say that this is a great success for Microsoft as Silverlight has just been rolled out in April 2007, however, as Silverlight is largely supported by Microsoft and it's automatically installed for the user by Windows Update we can say (for now) that the numbers for Silverlight are not accurate enough.
On the other hand, coming to the market penetration and global usage, Flash, Java, and Silverlight have penetration rates of about 96%, 79%, 60% respectively, said
StatOwl. So now we can say that Silverlight really made GREAT success in no time.
Another study of interest said that two of each four machine represent half of the machines in this world!…. Have a nice weekend!