Announced at Apple's Worldwide Developer Conference (WWDC) on June 10, 2013, the Safari 7/6.1[45] developer preview brought improvements in JavaScript performance and memory usage, as well as a new look for Top Sites and the Sidebar, and a new Shared Links feature. Additionally, a new Power Saver feature pauses Plugins which are not in use.[46] Safari 7 for OS X Mavericks and Safari 6.1 (for Lion and Mountain Lion) were released along with OS X Mavericks in an Apple special event on October 22, 2013.[47]