Application servers do not support Struts. The development tools do. This is because Struts is
J2EE compliant and will deploy to any compliant appserver.
About the IDEs for WebSphere and WebLogic, I don't know the extent of support for Struts. I do know WSAD has some wizards for creating Struts-based web applications and that there is for example a JBuilder WebLogic Edition which has similar wizards.