The Missing Safari Extensions Gallery Search Engine is here

Extensions can modify the appearance and behavior of Safari, and access your private information at websites. Apple is providing links to these extensions as a courtesy, and makes no representations regarding the extensions or any information related thereto. When you download and install an extension, the file is delivered by the developer, not by Apple. Some of the extensions listed here may require payment to the developer for use of the extension; this transaction is between the user and the developer. Any questions, complaints, claims, or support requests regarding an extension must be directed to the appropriate software developer.