The macro below displays a Countdown Timer...

<iframe src="http://free.timeanddate.com/countdown/i57958xg/n263/cf111/cm0/cu4/ct0/cs0/ca0/cr0/ss0/cac000/cpc000/pc66c/tc66c/fs100/szw320/szh135/tatTime%20left%20to%20Event%20in/tac000/tptTime%20left%20to%20New%20Year's%202017/tpc000/mac000/mptWashington%20DC/mpc000/iso2017-01-01T00:00:00" allowTransparency="true" frameborder="0" width="320" height="135"></iframe>

This macro links to a OneDrive folder to show a PowerPoint presentation using Microsoft software (i.e., not PDF)...

(Note: This macro can also be used to load Google Docs and other sources into a Wiki page). 

<iframe src='https://onedrive.live.com/embed?cid=A10540030BDAF112&resid=A10540030BDAF112%218958&authkey=AF2B2dfjIg-B2D0&em=2&wdAr=1.3333333333333333' width='610px' height='481px' frameborder='0'>This is an embedded <a target='_blank' href='Microsoft'>https://office.com'>Microsoft Office</a> presentation, powered by <a target='_blank' href='Office'>https://office.com/webapps'>Office Online</a>.</iframe>