The name "Haskal" says most about itself. It is derived from "Haskell" and "Skal" = Shell in Swedish.
Haskal is Unix-like Shell, which provides much additional functionality, that is, the power of Haskell language.
Haskal allows Unix commands to be used in combination with Haskell functions in order to establish much improved shell functionality.
Two simple examples are:
ls >|< map toUpper
ls -."l" #"/"
Haskal makes use of "hs-plugins" in order to load the Haskell code into the application at runtime.