RenPy - Ren'Py is a free and cross-platform visual novel engine that helps you use words, pictures, and...
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
TyranoBuilder - A Easy Visual Novel Development Tool!
Sottolio - sottolio is a game engine to make in a simple way visual novels for your internet browser.
Quest - Quest lets you create sophisticated text-based games, without having to program.
Sottaceto - Game engine to make in a simple way Visual Novels for Android just writing the script in a XML file.