Ren’Py is a free editor for visual novels. Download the SDK, run the launcher and use the jedit editor to modify the scripts.
Click here to download the tutorial. Copy the folder in your renpy project folder and run the launcher.
Advanced tutorial here
Notable visual novels/dating sims
Digital: A Love Story and most games by Christine Love
CAVE! CAVE! DEUS VIDET! based on Hieronimous Bosh’s work
Save the DateHatoful Boyfriend
Tusks: the orc dating sim
SC2VN – The eSports Visual Novel
Three fourths home
Saturday Night Symbiosis
Till Cows tear us apart