Modern graphical system monitor for any panel:

Multiload-ng is a modern graphical system monitor. It's a near-complete rewrite of the good old GNOME multiload applet, that aims to support every existing panel.

It supports the following panels:
- XFCE (xfce4-panel)
- LXDE (lxpanel)
- MATE (mate-panel)
- Ubuntu Unity (through libappindicator)
- Every panel with support for Application Indicators
- System tray (virtually any panel with a systray, in particular those without external plugins support, like tint2)
- Standalone (has its own window, not embedded in any panel)
- Avant Window Navigator (EXPERIMENTAL)

Multiload-ng can be built with GTK2 and GTK3, so can be embedded within GTK2/GTK3 builds of all the panels above.