Just before Christmas we announced basic X3DOM support for MS Internet Explorer 11. This is ongoing work and some of the more advanced features like BinaryGeometry (compact format) and PopGeometry are still missing or only partially supported.
Float binary data should work but quantized data (16 bit) does not, though it is an essential feature for large model visualisation.
Our goal is to get X3DOM fully working with the MS Internet Explorer 11. So we search for missing features, open bug reports and try to connect the IE developers directly. Therefore there is now, for instance, a ticket for the missing vertexAttribPointer types to get our BinaryGeometry completely work.