As you see over half of people now use Xojo 2017r2/r3. But a few still keep older versions like 2016r3, the last one before the use of DirectDraw.
The group with REAL Studio 2012 is still active, but shrunk a lot over time. Over time, it will be a question whether we should continue to support Real Studio with newer plugins.
On the OS Versions, you first notice that the majority uses Mac. The big growing green part is macOS 10.13 with is already in use on more Macs than 10.12 and more used than all the Windows versions.
Linux is not used much (blue on the bottom). Of course this sample is only from Xojo developers and may not be representative or accurate. But we may go and no longer support Windows XP for new plugins.