Read *.acsm pdfs online

Reading Digital Editions docs online

Adobe claim Digital Editions docs can be read both online and offline http://www.adobe.com/products/digital-editions.html

I'm trying to read a *.acsm pdf i've purchased online (e.g., so I can log onto an online Adobe Digital Editions account at work and read my texts without having to install new software on a work computer).

I've read around and found no support on this topic.

Does anyone know how?

thanks, Carl