Hi Dimitri,
Please may you describe a bit more your requirement and your Adobe Campaign version as well (ACS or AC v6.x.y/v7.0)?
ACS and AC v6/v7 have different possibilities including API, please confirm your environment.
Do you mean including Adobe Campaign webApp (standard or microsites) through html iframe object?
Or do you intend to display Adobe Campaign forms (XML forms) needing AC authentication and an operator account?
Or rather, as far as I guess from your request, do you want to develop your own html web form on your own web site, and call some Adobe Campaign SOAP calls to trigger some actions (deliveries, save profiles data in AC database, etc).
But in that case, the best thing is to do it at Web server side, not on the client, either in JSSP, or JSP, or php or .NET whatever your choice.
So there are no CORS issues because you can manage cross-domain on your Apache/Tomcat/IIS/nginx settings.
Regards.
J-Serge