World Championship Sports Network--which streams live and on-demand coverage of Olympic sports year round--announced plans to stream the 112th Boston Marathon live to a global audience for free. WCSN.com, which typically charges viewers a monthly or yearly fee to watch everything from equestrian to badminton on the Web, will deliver the free marathon event as the result of a joint sponsorship by Adidas and MarathonGuide.com. The site also plans to roll out a special editorial package surrounding the race, which begins at 9:25 a.m. EST on Apr. 21.The Boston Marathon is the second of the World Marathon Major events that WCSN.com plans to cover. Later this year the site will stream live footage from marathons in London, Boston, Berlin, Chicago and New York.