This test page has three embedded Curl applets one for each downloadable RTE version. If you have the version installed you will see the applet displaying its input parameters. If you do not, you will see a message with a link to the download page.

You need v5.0 of the Curl RTE to run this application.

The following link will direct you to the Curl download page.
You need v4.0 of the Curl RTE to run this application.

The following link will direct you to the page where you can download this older version.
You need v3.0 of the Curl RTE to run this application.

The following link will direct you to the page where you can download this older version.