Hello GHC developers! Now that D4904 and D4986 are merged, if you have recently built GHC then you can use "./utils/ghc-in-ghci/run.sh -fobject-code" to load GHC into GHCi (throwing on a "-j8" helps too). For me, this makes development far more pleasant, as often I can make a change and try it out in only 15 or 20 seconds. Thanks to Csongor Kiss for writing the initial ghci script, and Matthew Pickering for posting about it to the mailinglist, as otherwise I probably wouldn't have known about it. I wrote a blog post about the topic on my new blog: http://www.mgsloan.com/posts/ghcinception/ Once D5015 is merged, the explicit "-fobject-code" won't be needed. Once https://ghc.haskell.org/trac/ghc/ticket/15454 is addressed, it might not be needed at all, leading to even faster loading ;) Happy ghci-ing! -Michael