Many in the RS World are turning to the XML Parser from MicroSoft
Using XMLHTTP you can acomplish remote scripting but there are pit falls.
The biggest pitfall is calling a page in the same directory will crash the server.
There is nothing to install or download, the parser is supported by most browsers
This method uses an Iframe to accomplish similar functionality.
Other than this problem with the history bug in Netscape - JSRS works fine. Any browser that supports Ifames will work fine with JSRS and since the Iframe is now a standard I believe this is the better choice of the two.
For Compatibility with all browsers JSRS offers RSLite - This one uses image/cookie method to accomplish Remote Scripting.