For a Git branching strategy that allows parallel work on independent tasks, keeps the mainline always releasable, allows features to be abandoned at any time, and encourages experimentation, which approach do you recommend?

The correct answer is a single long-running branch with multiple short-lived feature branches. This strategy, often called Gitflow or GitHub Flow depending on specifics, allows developers to work on new features or bug fixes in isolation on their own branches. These branches are short-lived and merged back into the main branch (e.g., main or develop) once complete and reviewed. This keeps the mainline stable and always releasable, as experimental or incomplete work doesn't directly impact it. Features can be easily abandoned by simply deleting their branch. A single long-running branch without forking would lead to an unstable mainline, as all work directly impacts it. Multiple long-running branches can become complex to manage and merge. A single fork per team member is a common practice for open-source contributions but less efficient for internal team development, as it adds an extra layer of repository management.