Vimperator will stop working in up-to-date copies of Firefox with the release of Firefox 57 on November 14th due to a large breaking change in how extensions and add-ons are written (#705). It's not all doom and gloom, though! Here are your options (#729): Stay with vimperator, but use an older release of Firefox or a Firefox fork Basilisk, Pale Moon, and Waterfox Classic are community-maintained
