Last month I came across MyMaps by Google which claimed to be a tool to collaborate with others to create custom maps. I was surprised to find out this didn't mean real-time collaboration, rather asynchronous with user changes only updating when refreshing the page.<p>Because of this for the past weeks I've been working on a real-time collaborative map tool to make it easier to plan trips with friends. You can freedraw, make lines, areas, markers, find places and things to do nearby, observe other users, etc. Since real-time collaboration costs $$$$ I've made it open source and shared some instructions in the repo as to how to self-host it (or even commercialize it and turn it into a live product if anyone is interested, it's got an MIT license so go ahead!)
Wow, I had heard that Firebase was powerful but this almost fully featured program is just one html file, the leaflet js library, and is fully powered by Firebase on the backend.<p>I got it running locally on my machine without any trouble, this is super neat!