Ferret (GitHub: wincent/ferret) by Greg Hurrell is a search plugin that offers asynchronous search, multi-file replace, args list/argdo support, and QuickFix listing enhancements.

It supports The Silver Searcher, Ack, and grep. Asynchronous support is done with dispatch.vim — you have to install dispatch.vim if you want asynchronous searching.

I’ve been trying it out, and it feels very similar to my usual Silver Searcher plugin, so I’m going to stick with it for a few weeks to see if I prefer it. So far I definitely like the multi-file replace, and the QuickFix list looks good.