EarthBound (Mother 2 in Japan) holds a special place in the hearts of many, but despite the clamor for it, Nintendo has never officially released Mother or Mother 3 outside of Japan. Mother went through official localization but was put on indefinite hold, and insatiable fans translated Mother 3 to English themselves, releasing it in 2008 as a ROM hack.
All three English ROMs have been compiled by Mother fan Marcel Oliveira into one file for modded Wiis. In addition, he added a user interface that mimics an EarthBound battle sequence, allowing the user to choose which of the three titles to play by attacking it.
Emulating the unreleased Mother titles has always provided a bit of a moral grey area for many. Of course, downloading ROMs and modifying a Wii to play them come with their own legal and/or financial hazards. Proceed at your own risk.