NetworX is an editor, which lets you create maps for public transport systems. It features

• 4 different line modes, e.g. straight and curved
• Detailed positioning and rotating of the labels of even multiple stations at once
• Detailed customization of lines and stations via CSS
• Two-toned dashed lines (e.g. to represent only part-time service)
• Exporting to PNG or SVG images

Please note: NetworX is still in beta state. Minor and major bugs can appear. To contribute to the development, please report any issues.

To get started, I recommend reading the introduction article