in GNU/Linux

Samba public folder without password

write this to your smb.conf

comment = public
public = yes
writeable = yes
create mode = 777
path = /path/to/public
directory mode = 777
browsable = yes
guest ok = yes

make sure to chmod 777 the directory and have the following option on:

security = share

We use it as a temporary space and quick way to exchange files between linux, macos x and windows machines.
Be aware that *anyone* can read/delete/modify *every* file or folder located in the public folder.