The most important thing

VRML is not support by Microsoft Internet Explorer and Netsacpe, you have to install plug-in program to see this 3D world.
Since VRML has VRML1.0 and VRML2.0 two standards, so the user have to select the correct plug-in program in order to see it. Also, VRML2.0 plug-in doesn't means that it can read VRML1.0 file,

VRML 2.0 plug-in