The developer edition of both ColdFusion MX and 5 allows you to access the the server from the local server/machine via localhost or the IP equivalent 127.0.0.1 and a single other IP address.
The method used to keep store this information is that the first non-local IP address that accesses the server will be written into the license.properties file in the {CFMX}/lib.
With the ColdFusion 5 Developer Edition, you could only access the server from one IP as with MX, however the server 'forgot' the IP address that was stored each time the server was restarted.
With ColdFusion MX the server will remember the second IP address (localhost & non-local) permanently. The way to change the second IP is to edit the license.properties and then restart the server.