It's been more than a year since my last update on the status of X10. It seems nothing much is happening. X10.com is still announcing the reactivation of ActiveHome Pro on the horizon. Meanwhile, the CM15A and CM19A are sold without software but the last version of ActiveHome Pro (SW31A only; no plug-ins) is available free of charge. This version still asks that the software be registered but that step can be ignored. Unfortunately, it seems that the CM11A is no longer available.
According to the forum on tuicemen "Authinks [the owner of X10.com] is looking for a developer/s to rewrite AHP... Authinx also plans a few major improvements to the cm15a once a rewrite is finished. They also plan to release the protocol once a rewrite of AHP is done." Good news but that was about a year ago.
There seems to be help for the plugins at tuicemen. Something to test when I will give AHP a try on my new Windows 10 machine. Also according to the forum on tuicemen, there appears to be problems with ActiveHome Pro and 64 bit versions of Windows 7 and 10. Nothing is ever simple.