Razor Qt is a new lightweight desktop environment - think of it as an early LXDE, but using Qt. It doesn't come with a display manager or window manager and its developers recommend using it with Openbox, but it should work with any WM, like Kwin, Metacity, etc.
The latest version - 0.4 -, brings some important improvements such as (very) basic configuration tools, razor-runner program (a tool for launching applications), a menu as well as some panel plugins such as removable media (for mounting and unmounting removable media), a screensaver/lock screen plugin and a show desktop plugin.
For a full list of changes, check out the Razor Qt website.
Razor Qt looks a lot like KDE: it uses your current KDE theme (if KDE is installed) and it even has a plasma-like feature, but it doesn't come with any KDE dependencies and the whole source has a size of only 5.6 MB. While that makes Razor Qt very lightweight, it also means there are missing features, but it's already usable.
For instance, while the desktop supports widgets, there are only 3 widgets available: a clock, icon view and an example plugin; the panel has 9 plugins: clock, desktop switcher, application menu, removable media, quick launch, quick screensaver on/off switcher, show desktop, task manager and system tray.
Since Razor Qt doesn't come with its own applications, you'll have to install some Qt applications yourself. For the file manager you can use QtFM (which I've found to be quite interesting) or Andromeda. For more applications that use "pure" Qt (don't have any KDE dependencies), check out Pinguy's second post in THIS thread.
You can also find an official list of suggested 3rd party applications to get a fully featured Qt desktop, HERE.
If you have KDE installed, you'll notice that Razor Qt will use your KDE theme for the bottom panel, desktop right click menu and some applications. However, for some reason some parts look un-themed, like its menu (when opening it from the panel, not by right clicking on the desktop), at least that was the case in my test under Ubuntu 11.10 Oneiric Ocelot. This was basically the only issue I've encountered with Razor Qt (it was a quick test though) - well, besides some missing features which, however, are expected in a lightweight desktop environment, especially one that's still in its infancy.
How lightweight is Razor Qt? Well, in my test, Razor Qt used about 114MB of RAM on login (using Openbox as the WM, under Ubuntu 11.10) which is almost as lightweight as Lubuntu 11.10 (which used 108 MB of RAM in my test).
Hopefully we'll soon see a Linux distribution running Razor Qt, with all the Qt applications an user needs installed by default. And actually, Pinguy was so impressed with Razor Qt that he says he might create such a distro as a side project. We'll let you know if this happens.
Install Razor Qt
Razor Qt is available in a PPA for Ubuntu Lucid, Maverick, Natty and Oneiric users. Add the PPA and install Razor Qt using the following commands:
sudo add-apt-repository ppa:razor-qt/ppa sudo apt-get update sudo apt-get install razorqt
Then log out and then select Razor Desktop (with the desired WM) from the login screen:
For other Linux distributions, see the Razor Qt download page.
via PinguyOS forum; thanks to Antoni "Pinguy" for the tip!