Hi all,
Since more and more people are exporting glTF for direct use in Cesium or as part of 3D Tiles, the new glTF Validator project may be of interest:
You can run the command-line tool or drag-and-drop glTF assets to validate against the spec. Note that this is using the 1.0.1 spec, and there is just a tad more work to finalize the spec and update the sample models so you may see some warnings for sample models (like missing accessor min/max) that can be ignored until everything is updated.
For more glTF news, including exciting support from John Carmack, CTO of Oculus, see
Patrick