Nowadays with the device (mobile, tablet, desktop etc.) and connectivity diversity (3G, 4G etc.) that we know, serving an optimized information to specific environments is paramount (thought not that easy). Many techniques exist to answer performance issues, especially when it comes to images.
We have been waiting for it for a long time, it is now a reality: Bootstrap 3 (BS3) RC1 was released two weeks ago. BS3 is “mobile first” (which was also if I recall correctly the Foundation 4 motto at the time of the release: March 2013… What can be more trending than this?!). While Bootstrap 2 (BS2), has optional mobile friendly styles, Bootstrap 3, is mobile friendly from the start.