Although Ansible only works on POSIX, you may want to edit your inventories and playbooks on Windows. This is a problem if you use any files or values encrypted with Ansible Vault. It may be a pain to find a separate POSIX machine just to run the ansible-vault CLI to encrypt/decrypt these vault files. This is an OS-independent port of a simplified version of just the ansible-vault CLI so that you can work with these encrypted files on Windows.
See the ansible-vault docs for more info.