| cairoSurface | Helm.Engine.SDL.Asset |
| CalculatorKey | Helm.Engine, Helm.Keyboard |
| CancelKey | Helm.Engine, Helm.Keyboard |
| CapsLockKey | Helm.Engine, Helm.Keyboard |
| CaretKey | Helm.Engine, Helm.Keyboard |
| center | Helm.Graphics2D |
| circle | Helm.Graphics2D |
| CKey | Helm.Engine, Helm.Keyboard |
| cleanup | Helm.Engine |
| ClearAgainKey | Helm.Engine, Helm.Keyboard |
| ClearKey | Helm.Engine, Helm.Keyboard |
| clicks | Helm.Mouse |
| clip | Helm.Graphics2D |
| ClippedJoin | Helm.Graphics2D |
| Cmd | |
| 1 (Type/Class) | Helm.Engine, Helm.Cmd, Helm |
| 2 (Data Constructor) | Helm.Engine, Helm.Cmd, Helm |
| Collage | |
| 1 (Type/Class) | Helm.Graphics2D |
| 2 (Data Constructor) | Helm.Graphics2D |
| collage | Helm.Graphics2D |
| collageCenter | Helm.Graphics2D |
| collageDims | Helm.Graphics2D |
| CollageForm | Helm.Graphics2D |
| collageForms | Helm.Graphics2D |
| ColonKey | Helm.Engine, Helm.Keyboard |
| Color | |
| 1 (Type/Class) | Helm.Color |
| 2 (Data Constructor) | Helm.Color |
| color | Helm.Graphics2D.Text |
| CommaKey | Helm.Engine, Helm.Keyboard |
| complement | Helm.Color |
| ComputerKey | Helm.Engine, Helm.Keyboard |
| CopyKey | Helm.Engine, Helm.Keyboard |
| croppedImage | Helm.Graphics2D |
| CrSelKey | Helm.Engine, Helm.Keyboard |
| CurrencySubunitKey | Helm.Engine, Helm.Keyboard |
| CurrencyUnitKey | Helm.Engine, Helm.Keyboard |
| CutKey | Helm.Engine, Helm.Keyboard |