This QGIS Plugin, Qgis2threejs, exports terrain data, map canvas image and vector data to your web browser!!
All you have to do is opening the DTM in Qgis (2.4.0 Chugiak), go to plugins library and install Qgis2threejs.
Then choosing the parameters of the visualization and voilá!!
I have used a 5m DTM which source was LIDAR so the quality is very good
Hope you guys like it. Feedback would be greatly appreciated.
MSc GIS and Quality Control
albertoconcejal [at] gmail.com