Thunderbird-Tray!

Allows almost any program to be minimized to the system tray by right clicking its minimize button.

FireTray is a Linux Mozilla addon that targets Mozilla Firefox, Thunderbird and SeaMonkey. It provides a system tray icon with much window handling functionality. For mail applications, the icon can show the number of unread or new messages. FireTray is very customizable.

SmartSystemMenu extends system menu of all windows in the system. It appends next custom items to menu:

PowerMenu is a small application that some extra menu items to the windows control menu in addition to the standard "Close", "Maximize", etc options. The extra menus are: Priority, Always On Top, Transparency and Minimize To Tray.

Clicky Gone allows you to hide your selected windows from view, this includes the taskbar button associated with the application. This utility particularly helps with protecting your privacy by hiding things like your browser with banking details up and someone walks in on you.

TopMenu is a functionality clone of PowerMenu, but designed to be compatible with Windows 7 and 64-bit systems.

TrayIt! - minimize to the system icon tray any program (Outlook Express, Notepad, Word, Internet Explorer, Sunbird, Thunderbird, Opera, OpenOffice etc.) and get more room in the Taskbar!

AllTray is a program you can use on Unix-like systems such as GNU/Linux or FreeBSD running the X Window System to dock any application which doesn’t have a native tray icon into the system tray/notification area. AllTray works with many desktop environments and window managers, including Metacity on GNOME and KWin on KDE. The current release of AllTray is 0.7.2dev, and can be downloaded from Launchpad; the most recent stable release is 0.70 and is also available at that location

KDocker will help you dock any application into the system tray. This means you can dock Openoffice, xmms, Firefox, Thunderbird, anything!

Process Manager for Windows is a utility which allows you to to set process priority, minimize windows to the system tray, and more—all via taskbar window button right-click menus.

Trayconizer allows you to minimize virtually any application to the system tray rather than having it take up valuable space in your taskbar. The screen shot to the left shows Trayconizer minimizing Notepad to the system tray.Using Trayconizer is simple. To start Trayconizer on Notepad, you would execute: C:\Path\To\Trayconizer.exe C:\Windows\Notepad.exe.

WLM Tray Patch is a small tool that will patch your Windows Live Messenger 2011 and force it to minimize to the system tray in Windows 7 instead of staying at the task bar just like in Windows Vista. No more running WLM in compatibility mode which causes stability and security problems.