What is Twine?
Twine is an open-source tool for telling interactive, nonlinear stories.
Twine publishes directly to HTML, so you can post your work nearly anywhere. Anything you create with it is completely free to use any way you like, including for commercial purposes.
[From the website]
Comments and Reviews
Said about Twine as an alternative
This is one of two software I was deciding between and after working with both I decided to go with Ren'py, but I see myself using both in the future depending on situation
It's very easy to use. You don't have to have any coding knowledge (although that certainly helps). You can use it to map chats for another game, but also to create interactive fiction that stands on its own.