The engine version selection will be achieved using a htaccess configuration file.  A htaccess file allows you to set and alter various web server options for the current directory and all it sub-directories.

To do this, create a file named .htaccess in the appropriate directory.  If you want the changes to effect all your scripts, place it in your public_html directory.  Otherwise, place it in the desired sub-directory.

Next, you need to choose the file extensions you want to effect.  By default, the .lc extension maps to the latest build of the LiveCode server engine.  The .irev extension maps to the RevServer engine.  You can either create a new extension to map to specific engine versions (e.g. .lc463, .lc464) or just overwite the defaults (.lc and .irev).

To add the extension, you need to create a new line in your htaccess file.  The line is of the form:

AddHandler <extension_name> <extension>

Some examples of this are as follows:

AddHandler livecode-script .lc
AddHandler livecode-463-script .lc463

AddHandler livecode-464-script .lc464
AddHandler irev-script .irev

Now that you have added your extension, you must map it to an engine version.  To do this, you need to add a line to your htaccess file of the following form:

Action <extension_name> <engine_path>

On the On-Rev servers, the server engines are all located in the directory cgi-bin.  The RevServer engine is located at /cgi-bin/ireviam-engine.  The latest LiveCode server engine is located at /cgi-bin/livecode-server.  Particular server engine versions can be found at /cgi-bin/livecode-server-<version_number>.

So, for example, your htaccess entries could take the following form:

AddHandler livecode-script .lc
Action livecode-script /cgi-bin/livecode-server

AddHandler livecode-463-script .lc463
Action livecode-463-script /cgi-bin/livecode-server-4.6.3

AddHandler livecode-8-script .lc
Action livecode-8-script /cgi-bin/livecode8/livecode-community-server

AddHandler irev-script .irev
Action irev-script /cgi-bin/ireviam-engine