bash-3.2$  ghc-pkg list 
/opt/local/lib/ghc-7.6.3/package.conf.d
   Cabal-1.16.0
   array-0.4.0.1
   base-4.6.0.1
   base64-bytestring-1.0.0.1
   bin-package-db-0.0.0.0
   binary-0.5.1.1
   blaze-builder-0.3.1.1
   blaze-html-0.6.1.1
   blaze-markup-0.5.1.5
   bytestring-0.10.0.2
   containers-0.5.0.0
   data-default-class-0.0.1
   data-default-instances-base-0.0.1
   data-default-instances-dlist-0.0.1
   data-default-instances-old-locale-0.0.1
   deepseq-1.3.0.1
   digest-0.0.1.2
   directory-1.2.0.1
   dlist-0.5
   extensible-exceptions-0.1.1.4
   filepath-1.3.0.1
   ghc-7.6.3
   ghc-prim-0.3.0.0
   haskell2010-1.1.1.0
   haskell98-2.0.0.2
   hoopl-3.9.0.0
   hpc-0.6.0.0
   hs-bibutils-5.0
   integer-gmp-0.5.0.0
   mtl-2.1.2
   old-locale-1.0.0.5
   old-time-1.1.0.1
   parsec-3.1.3
   pcre-light-0.4
   pretty-1.1.1.0
   process-1.1.0.2
   rts-1.0
   syb-0.4.0
   template-haskell-2.8.0.0
   text-0.11.3.1
   time-1.4.0.1
   transformers-0.3.0.0
   unix-2.6.0.1
   utf8-string-0.3.7
   xml-1.3.13
   zlib-0.5.4.1