not sure if kde can be considered as having ever been lightweight. as far as I remember it was always one of the most heavy DE's around.

edit: I'm rate-limted[x] from commenting for defending myself against people calling me a brown-nosed European and white supremacist so I can't really reply below to @Crinus:

here reply inline:

oh I didn't know about v1, I think the first version I used was kde2 and that was the heaviest option you could install back then (iirc).

fwiw my comparison to i3 above isn't really fair. one is just a WM the other is a full-blown DE.

[x] https://news.ycombinator.com/item?id=19633128

Kubuntu => KDE

Xubuntu => xfce

Can linux-desktop stand more fragmentation?

Xubuntu has existed for at least 8 years not. Possibly much longer.

Since 2006[0]. I remember looking for a small user-friendly distro in 2008/9 that would fit my college-issued laptop's OEM emergency partition (5-ish GB). That partition was never used, as reimaging was the solution to almost every problem, yet they never bothered to delete it from the official images.

In the time and machines since, I've kept using Xubuntu.

[0] https://en.wikipedia.org/wiki/Xubuntu

I used Xubuntu for many years, but somehow having my own Linux machine became less and less important, even as a developer.

Now I just have Windows 10 and macOS Mojave.

For Linux stuff, I spin up a Cloud9 EC2 instance.

And? This is somehow solves fragmentation problem?

KDE1 was very fast and lightweight, i used it back when it was new via Caldera OpenLinux on a PMMX with 32MB RAM and i was very impressed not only with how fast it was but with how much stuff the CD came with (although that was largely due to the excellent - and unreplicated - work of the people behind COL)- and proceeded to do what every self respecting teenage nerd that learned about Linux does: install it on every friend and relative's computer, permission optional of course :-P

No really, KDE1 was very fast - try COL 2.3 CD from archive.org[1] and put it in PCem or 86box with an emulated Pentium MMX at 166MHz and 32MB of RAM and see it for yourself.

Later versions bulged and bloated and i do not think it ever felt as lightweight, but at least version 3 was rock solid. Of course this meant that KDE4 had to be rewritten from scratch and become a bloated buggy mess, as is tradition on the Linux desktop (also see GNOME 3 and i'm going to be very disappointed if XFCE doesn't become slower and bloated after it fully switches to GTK 3).

[1] https://archive.org/details/OpenLinux2.3CD

You forgot Enlightenment. Back to later 90's/early 2000's was the most heavier thanks to the quantity of FXs(Without using GPUs or composition...) that it had.

E17 had a compositor and hardware rendering before Xorg/XFree86 had (making it smoother and using the GPU instead of CPU). Its just that it was in an eternal state of beta.

What is lightweight? This is actually a complex question. Back in the day KDE has the largest in memory footprint when you first started up, but once you launched a realistic set of apps: suddenly KDE (using only KDE apps) has by far the smallest memory footprint.

My personal arbitrary definition is something that is usable without noticeable lag on a Raspberry Pi 1.