Yes, Flash Remoting is supported with ColdFusion. We do not currently support plugins for other languages such as .NET.
To test if Flash Remoting is working on your site, please open the following link in a browser (substituting www.yourdomain.com with your domain name):
http://www.yourdomain.com/flashservices/gateway
You should receive a blank page. If you receive an error message instead, there is a problem with your configuration. If such a case exists, please notify us by submitting a support ticket and we will be glad to assist you.