GHC's functionality can be useful for more things than just
compiling Haskell programs. Important use cases are programs
that analyse (and perhaps transform) Haskell code. Others
include loading Haskell code dynamically in a GHCi-like manner.
For this reason, a lot of GHC's functionality is made available
through this package.

See <https://gitlab.haskell.org/ghc/ghc/-/wikis/commentary/compiler>
for more information.