Passwd is the Horde password changing application. It provides fairly complete support for changing passwords via Poppassd, LDAP, Unix expect scripts, the Unix smbpasswd command for SMB/CIFS passwords, Kolab, ADSI, Pine, Serv-U FTP, VMailMgr, vpopmail, and SQL passwords.
To change your password
Change password, see the section called "Absolute basics" and the section called "SUID and SGID".
Change password, see Section 2.2 and Section 4.1.6.
passwd change local or password information
Unix and Linux systems used to change a user's password. A key derivation function is used to encrypt the new password. Only the encrypted version is stored.