Some forum members told me I should give Concrete5 a try. I set up a subdomain, used the one-click install, went to the admin page to complete the install, filled in an admin password and the mysql parameters, chose the option to get a test page rather than an empty page, hit the install, which ran for a while but came back with Internal Server Error "The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, email@example.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."
I looked at the MySQL database with phpMyAdmin and found 125 tables had been created. Hitting the back button from the error screen also reports these tables exist.
Don’t know what else to check out.