Hi, on the GHCJS website () I found an information:

If you are from the future, you have GHC 7.8 or higher installed, and Cabal 1.18, run the following:
$ cabal install ghcjs
$ ghcjs-boot --auto

Is it possible currently to get somehow GHC 7.8 or this information means that AFTER release of 7.8 this functionality will be available?