TIBCO EMS as interfaces for : C, COBOL, Java EE, and .NET. They require code (libraries) from TIBCO, under license (might be included when you acquire EMS).
For example, to submit a message to EMS from Java, you must use the JMS framework (part of Java), but you code still require the (non-free) EMS .jar.
To submit to EMS from a Web Form, you would typically use some form of integration, like a Web Service (possibly Java or BusinessWorks based), that transfers the data to EMS.
Note : Some other messaging products, like ActiveMQ, support a direct AJAX interface.