X3D (Extensible 3D Grpahics)is going to be the successor of
VRML97. The
Web3D-Consortium and the
W3C are working on the Standard, which is likely to become an
ISO Standard as VRML2002
It is based on XML and will be backward-compatible to VRML97.
It is going to have a relativly small core and a lot of components extending it. That makes it fast.
Theres also going to be an open source X3D Browser written in Java called Xj3D