# ghci > The Glasgow Haskell Compiler's interactive environment. > More information: . - Start a REPL (interactive shell): `ghci` - Start a REPL and load the specified Haskell source file: `ghci {{source_file.hs}}` - Start a REPL and enable a language option: `ghci -X{{language_option}}` - Start a REPL and enable some level of compiler warnings (e.g. `all` or `compact`): `ghci -W{{warning_level}}` - Start a REPL with a colon-separated list of directories for finding source files: `ghci -i{{path/to/directory1}}:{{path/to/directory2}}`