This is a very basic implementation of Conway's Game of Life that I made partly as a testbed for other experiments, and also to brush up on Svelte and other web technologies.
You can edit the board and run it forward. It also has a way to save and load states from a string that encodes the size of the board and its state. (For instance, the state of the board above is encoded by life:16x16,00000800080e08c00124e210012408c0080e080000000080004001c000000000.)
To run it, with Svelte installed, go to the project directory and type:
$ npm run dev
This will run the page at http://localhost:5000 by default.