4.0.0 seems to be released soon. My small blog is mostly based on plain Bootstrap with a few color changes. I will
try to upgrade from Bootstrap
3.3.6 to version
v4.0.0-alpha.5. This post will just
document the changes that I have noticed while upgrading.
Bootstrap responsive embed can be very helpful to show responsive PDF files or videos. But it supports only the aspect ration 16by9 and 4by3. But what about other aspect rations? For example 210by297 would be interesting to embed a A4 paper.