Mulberry is a Cross-platform Mail / Contacts / Calendar Client that supports Sieve script generation and upload via ManageSieve.

The Thunderbird Sieve extension provides ManageSieve support for Mozilla Thunderbird.

TrustedBird, an e-mail client based on Mozilla Thunderbird, supports vacation notifications and redirections using Sieve.

Polymer (TRAC site) is an email client (IMAP, Lemonade, ACAP, Submission, …) that also supports ManageSieve.

kio_sieve manages mail filtering Sieve scripts remotely in KDE, via ManageSieve.

gsieve manages Sieve scripts for the GNOME Desktop, via ManageSieve.

Simon Josefsson has an Emacs-based ManageSieve implementation.

Sieve is an open source sieve script editor and ManageSieve client for Mac OS X 10.6+

Avelsieve is a Sieve mail filter plugin for Squirrelmail Webmail.

Ingo is a mail filtering manager, supporting Sieve, procmail, and IMAP filters. Part of the Horde framework.

Roundcube Webmail has Sieve & ManageSieve support since version 0.3.

Smartsieve is a web based graphical user interface for creating and managing sieve scripts on a cyrus IMAP mail server.

Websieve perl/cgi web module for creating scripts from Alain Turbide.

Xuheki Webmail supports editing/generating Sieve scripts starting version 0.4.

Cyrus IMAP comes with the sieveshell client for ManageSieve

sieve-connect is a Perl sieveshell-compatible ManageSieve client intended both for scripting and interactive use; supports TLS, certificate-based authentication support and tab-completion.