I’ve mostly used Word for requirements/user stories, you can turn on track changes. I’ve mostly used excel for WBS. I’ve also seen things like JIRA and Trello

I’ve mostly used Word for requirements/user stories, you can turn on track changes. I’ve mostly used excel for WBS. I’ve also seen things like JIRA and Trello used for small projects where you don’t need a formal requirements doc and you’re running it scrum or Kanban. My experience is mostly in non-technology industries.