The main source of information on Haskell is www.haskell.org.

The main software is the Glasgow Haskell Compiler, ghc, with its interactive system, ghci. This system takes 15 minutes to download, requires almost 1 Gb of disk memory. For the casual user the much smaller interactive system, hugs, is to be preferred.

Running hugs

1. Download hugs for your platform from from hugs. For a Windows computer the minimal system, MinHugs, is fully adequate.
2. On linux/mac the program is used from the command line. The windows version has a simple GUI. You can enter expressions directly. Try 1+1 followed by RETURN. You can tell Hugs to show the type of each expression by giving the command

         :set +t
       

   Definitions of functions and other values are written in a separate file using your favorite text editor and load or reloaded using

         :load filename
       

   or

         :reload
       

   Exit the system by CTRL-D.

Running ghci

1. Download the system from haskell.org. Installation is very simple. The program is started from the command line by the name ghci.
2. You can enter expressions directly. Try 1+1 followed by RETURN. You can tell Hugs to show the type of each expression by giving the command

         :set +t
       

   Definitions of functions and other values are written in a separate file using your favorite text editor and load or reloaded using

         :load filename
       

   or

         :reload
       

   Exit the system by CTRL-D.