Quote : Debian is definitely a good alternative to Ubuntu, but its nothing like “lightweight”. Structurally they are the same thing, running the same applications and services. So RAM and CPU usage would be same.

My experience is totally different : I switched from Ubuntu (after Unity mess) and Linux Mint (got buggy by time) to Voyager (Xubuntu spin) finally to Debian Wheezy with XFCE and am more than happy to have done so. CPU usage is far below anything before, system is super snappy and u get rock solid stability on top. CPU temperature (on i3 notebook) is always at least 20° celsius lower than I had with any Ubuntu and or derivative before.

So I highly recommend giving Debian a try, if u need newer software u might give testing a try or siduction/makulu/solydX.

Puppy is a portable distro and it can be installed only if you really really need it. It is written in clear letters in the documentation.
“Puppy is easy to use and does not require a hard disk, so the first trick that you must know is how NOT to install it to hard disk !”
http://puppylinux.org/main/How%20NOT%20to%20install%20Puppy.htm

But besides that, Puppy is obviously a “toy” distro, one that can appeal geeks but not regular users because of two reasons, the ’90s look and the deluge of tiny tools available in the menu that make it confuse. People who want to revive old hardware need software that makes sense, lets say something that can replace Windows 2K or XP, not an experiment like “you can run Linux over a wristwatch”.

On my old PIII with Debian XFCE you can do the following things:
Browse the Internet with Firefox 24, play with pictures with Ristretto, MTPaint and even Gimp (given that you are patient), open documents with AbiWord or even Libreoffice (again, patience) . There are only two things that don’t work, Flash stopped working with that CPU because of a bug and you must use an old version, which then makes Firefox upset and it tries to disable it and videos that obviously lag depending on the quality/size.

I have tried ALL the suggested distros for “old hardware” and they are mostly unusable because they are “toyish” (like Puppy) or they don’t offer a sensible gain compared to Debian (like Antix).”

There are many small linux distros for old and slow hardware and puppy is one of them, so the user has plenty of choices available. Such distros use older kernels which are smaller, fasters, support older hardware.

Puppy linux is not meant to be a portable distro and it lacks the features to be so.
Distros like slax and porteus are better options for portable linux.

Debian is definitely a good alternative to Ubuntu, but its nothing like “lightweight”. Structurally they are the same thing, running the same applications and services. So RAM and CPU usage would be same.

And lastly, having a lightweight desktop like Xfce just reduces the footprint on the desktop. But does not make the distro swift enough to run on older or low spec hardware. It will boot fine on a PIII 256MB system, but the moment you start using standard heavyweight applications it will start to lag.

So basically there are 3 components, the linux system itself, the desktop environment and the applications.

The alternative to Ubuntu based distros is simply Debian, which is light and offers a full fledged system. The main issue with Debian for the Xubuntu user is that the XFCE version comes with GTK2 only themes and old Tango icons, so it looks “wrong”. It can be configured to look exactly like Xubuntu but it takes some work. You need to install the Murrine GTK engine, a package named “gtk2-engines-pixbuf” and then you need to copy icons and themes from Shimmer project. Tested on a PIII system with 256 MB of RAM.