This was designed by one of Wikimedia Foundation's visual design fellows, Michelle Nguyen (http://michellemeng.com). It was created through the exploration of hand lettering styles and the origins of the very well known phrase, hello world. Combining the two shaped this illustration to have a fun take on the phrase, paying homage to the computer world, highlighting Wikipedia's presence, and an announcement of existence -- perfect for a baby onesie, which was what this was primarily designed for.
Own work
MNguyen (WMF)