He is widely known for using this client for the majority of his anarchy and event videos (such as the MCPVP events) due to its utility features and compatibility with the anarchy server playstyle.
Many older Wemmbu fans remember his "Dream vs. Wemmbu" cheating exposal series. Ironically, the (not to be confused with YouTuber Dream) is a free, open-source cheat that Wemmbu used on alts.
Win + R, type %appdata%, and open the .minecraft folder.Cmd + Shift + G, and type ~/Library/Application Support/minecraft.