I 'm using a visual novel engine called Ren'Py. It's extremely flexible if you learn the basics of the Python programming language. I tried other classic japanese visual novel engines like Kirikiri but I found Ren'Py easier.  Also the engine is always being updated (for over 15 years now) and the lead developer is easy to contact and dialogue with. Nothing beats that. Also, it's free, check it yourself, it's fun.

Also you don't need to know programming to be able to use it (I knew nothing at the beggining),  the only thing to learn is the scripting language which is very simple. Let me show you a sample of how you can show a character and make her talk:

My goal is to give the player the classic ADV game experience. In order to do that, I have to customize everything in Ren'Py from the keys to the menu screens, for which I plan to write modular plugins for each of this functionalities. For example, I am working in CG gallery plugin which lets the developer build a gallery automatically from a folder just by naming the images accordingly without any more work.

Let me show you just a taste:

I know it seems illegible for a non-programmer but this is just to show you what I am working on. Basically, if you learn Python, you can do almost whatever you want.

In conclusion, Ren'Py allows me to build a framework to create games from classic visual novels to even RPGs. Honestly, I started this whole thing to make visual novels, but I found a passion to programming along the way, so it's a win-win.