Bert --
I looked into this a little more after I posted.
Greenway is not going to produce any further updates.
For now, they are providing telephone support if we run into trouble -- which, thankfully, very rarely occurs. I hate to leave a program that has served so well.
However, after they stop updating, the program will become obsolete after some period of time.
I'm fairly confident we can use it for another year or two.
The other part of this is my now suspended plan to switch to AC billing.
I'm now going to wait for a while to see what Harris has up their sleeve. I got a nice email (unsolicited -- he was just responding to a post on this board) which assured me that they really intend to go forward with AC. And they seem genuinely concerned about their clients.
So I am cautiously hopeful.