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.

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.

avelsieve is a user-friendly Sieve mail filter plugin for Squirrelmail Webmail.

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

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.

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.