Opus is a framework for creating visual novel with Unity. It is an open source Unity project, with all basic features you would except in a Visual Novel already taken care of.
It uses simple and extensible XML files to define the structure of the game.
Opus is not a "make a visual novel without code" tool. Even if a lot of the heavy lifting is already done, there are still some things you are expected to do yourself. This is because I want Opus to stay simple and barebone while still being extensible.
Coming soon.
The code is a mess right now (though a functionnal mess), so I am not in favor of adding features until the actual thing is not cleaned up.
There are two scenes in the project, Title and Game. The main thing is the VisualNovelManager script in the Game scene, which will read the XML files in the Resources folder and make the game progress, so I would suggest beginning here.