At the DConf 2017 hackathon I adventurously led a druntime group (of 2 persons) hacking on D’s GC. After a few hours I couldn’t shake off the nagging feeling “boy, this could use a rewrite”. So I decided to start on the quest of better GC for D, the first iteration being faster classic mark-sweep collector. To explain my motivation I’m going to describe the internals of current GC, enumerating iss