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




AllTray is described as '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' and is an app. There are more than 10 alternatives to AllTray for a variety of platforms, including Windows, Linux, PortableApps.com, Thunderbird and X11 apps. The best AllTray alternative is SmartSystemMenu, which is both free and Open Source. Other great apps like AllTray are KDocker, RBTray, Actual Window Manager and 4t Tray Minimizer.
SmartSystemMenu extends system menu of all windows in the system. It appends next custom items to menu:




KDocker will help you dock any application into the system tray. This means you can dock Openoffice, xmms, Firefox, Thunderbird, anything!
Just point and click. Works for all NET WM compliant window managers - that includes KDE, GNOME, Xfce, Fluxbox and many more.



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





4t Tray Minimizer is a lightweight but powerful window manager, which helps you to free up space on the desktop and the taskbar via the following actions:




DM2 provides several Windows enhancements that may help in every-day work. One of the nicest and most popular features of DM2 is minimizing windows to floating icons® (unique feature!) freeing both task bar and tray bar space.


The Wonderful Icon is a small Windows utility that resides in your PC's taskbar tray. With it, you can:

FireTray is system tray extension for Linux and Windows that targets Mozilla Firefox, Thunderbird and SeaMonkey.



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!



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.



Minime is a tool that allows you to minimize applications to the system tray using a simple hotkey. What makes this tool somewhat unique is that it keeps your system tray clean by minimizing all applications into a single tray icon.

KDocker is more advanced. It remembers the window position, so it undocks it to the same position it was before being docked. It also has many configuration options directly inside the docked app's systray icon context menu, notably the possibility to set a custom icon for each docked window (useful when the app doesn't have its own icon).