Eclipse can be setup to display code in an infinite number of ways. The following settings are how I like to configure the Eclipse Force.com IDE.
- Spaces instead of tabs
- Show line numbers
- Show whitespace characters
- Show a print margin
These settings can be changed at: Window -> Preferences -> General -> Editors -> Text Editors
Click the “configure visibility” link next to the show white space setting to add fine tuning. I always uncheck the the trailing carriage return and line feed boxes and increase the opaqueness.