In the initial
version of WorldWideWeb, the first web browser ever
(1990), even still pictures where displayed in separate windows.
They were included in the text later on (1993), when
the NCSA-Mosaic browser introduced the img tag in HTML.
Integration of continuous media objects, in particular video,
followed the same way, but much later. For a long time,
these objects were handled by separate programs (plug-ins)
and were therefore difficult to integrate in the document.
Only when SMIL introduced the video and audio elements
could web documents really include continuous media. SMIL
was followed in this direction by SVG and more recently by
HTML5. All three languages now support audio and video
objects natively.