react-router, react-router-redux, immutable.js was dead at some point when the only dev maintaining it left Facebook (AFAIK, I don't know if it got resurrected since) and people were just moving to immer.js. These are just on top of my head stuff that I had to replace when starting new projects because I didn't want to start a new project on potentially unsuported libs, there were more but I can't remember the names exactly - been a while since I was boostraping a new project.