Wgrep provides master pattern buffers that are then used to edit multiple Emacs buffers simultaneously. In this sense it is like what a REPL for sed would look like. With the exception of "pattern buffers" it is similar to the Emacs built-in functions `replace-regexp` and `query-replace`. Wgrep also provides backends that use Ack and The Silver Searcher.

This package enhances helm-grep-mode buffers with Wgrep's facilities, and is similar to helm-ag.