When the Sugar environment was first created it made a lot of use of Hippo Canvas and so did some Activities.  Lately Sugar Labs has reconsidered that and Sugar 3 will use no Hippo Canvas at all.  For this task write a chapter for Make Your Own Sugar Activities! that explains how you can take an Activity that currently uses Hippo Canvas and convert it to use regular GTK components and preserve the look and feel of the original as much as possible.  You will need an account on booki.flossmanuals.net to write this chapter.