# ghc > The Glasgow Haskell Compiler. > Compiles and links Haskell source files. > More information: . - Find and compile all modules in the current directory: `ghc Main` - Compile a single file: `ghc {{path/to/file.hs}}` - Compile using extra optimization: `ghc -O {{path/to/file.hs}}` - Stop compilation after generating object files (.o): `ghc -c {{path/to/file.hs}}` - Start a REPL (interactive shell): `ghci` - Evaluate a single expression: `ghc -e {{expression}}`