With the plethora of potential interfaces available
- lxde,
- openbox,
- fluxbox
- xfce,
- gnome2,
- gnome3,
- unity-3d,
- unity-2d etc,
my question is - what is meant by "the lightest desktop interface" - and can you now consider Unity-2d as "Light"?
Any guidance on the pro's and con's would be extremely useful for my evaluation - my target computer is a
- Pentium 4 1.3Ghz, 512Mb, 32GB HDD, 1024x768 Monitor, Geforce FX5500 256Mb AGP
I would like to use it for web-browsing such as youtube, google-earth, simple graphical picture editing and word processing - all aimed for school student aged 10-15 yrs.
A light interface is basically one that uses little resources, and can optionally depend on compositing and/or 3D capabilities, so even compiz could be called a light desktop interface when configured correctly (I've run compiz on worse specs than those you mentioned and it was fast and pretty stable).
For optimum performance, I would suggest going with Lxde (Lubuntu).
You can also use GNOME or XFCE, but keep in mind that both may get stressed under a heavy work load with that little memory, though you should be safe either way if you are only doing the basics like web browsing, word processing, etc.
Unity 2D is also a light interface, and might be able to run on your hardware.
Just to make this page more complete I would like to suggest Enlightenment as an option.
It is claimed for some to be the lightest Desktop Environment (DE), although it is a matter of opinion.
There are distros based in this DE such as Bodhi Linux, but you can install it (click here) in any Ubuntu and then logout and before log back in choose Enlightenment.
If you want everything to run smooth with those system specs, I would go with Xfce or Lxde.
Openbox and Fluxbox are simply Window Managers and while being extremely light weight there is a lot of configuring involved.
I'm not saying Gnome or Unity (which is Gnome with Compiz) won't work. It just might not be that quick and snappy.
Given your configuration I would suggest XFCE, it is pretty good and very similar to GNOME 2 but light on resources.
I can tell you I've tried it all end always end up with Lubuntu. I recently purchased a brand new netbook with latest Atom CPU and ION2 (GPU) and on Unity/Ubuntu 11.04 it was like swimming with clothes on. Even when running Unity-2d. I reverted to Lubuntu and it was a totally different experience, everything snappy and smooth. Mem usage down from ca 600MB idle 200MB!!!!
Then I've found out Openbox is undervalued it is indeed very powerful and robust if you have some time to read the guides and make your own customization. You could skip the LX desktop altogether, running without panel & launcher if you like and then you would have even more resources available. But it takes time and your gain is not as much as by just installing clean Lubuntu/LXDE from Ubuntu.
Hate to say it but Ubuntu is getting bulky like an elephant. Unity is nice but man it does eat your resources, a little easier with memory than the Win7 installation I had preconfigured but not any much faster (webbrowsing, watching video, loading apps etc...)
In my opinion the best available windows manager is ICEWM. It is simple, stable and you can make it any thing. PS: while using it you may get a feel of using a stone age windows manager (windows 95 etc.) but its worth it. You can configure it too look like windows 7 as well :)