Post-mortem of KDE 4-series 2008-2015
KDE 4.0 was released on 11.1.2008, with KDE 3.5.10 being the last version of the old order. KDE's new Plasma was a very ambitious project. It was supposed to combine cutting-edge semantic desktop system where everything is connected into a modern, uniform, network transparent and customizable desktop environment. There was only a small problem: it didn't work. Plasma and everything shipping with it on day one were borderline unusable. It took the project four point releases to make the system somewhat usable. As years went by, KDE still struggled. KDE became pretty much synonymous with glitch and crash. Not a single enterprise distribution ended up using KDE in these years. While being largest global collaborative open-source project after the Linux kernel itself, KDE remained in the fringes. Users were flocking to GNOME, XFCE, LXDE and later on to Mint. Few distro spins such as Kubuntu and Chakra aside, no major distro adapted KDE as the primary desktop. openSUSE was widely regarded as the only exception due its heavy focus on polishing KDE, but in the end even SUSE Linux Enterprise Desktop which is derived from openSUSE went with way more stable GNOME every time. Why did this happen? Could it have been avoided?
In order to reach uniformity and interconnectedness of the entire system, KDE adopted a massively monolithic development model. KDE became a SC, a software compilation, where the KDE Plasma desktop was just part of the whole. Everything from underlying libraries to applications like Dolphin was to be updated all at once to ensure that interoperability remained good. That sounds reasonable in theory, but in practice everything went to hell. It wasn't until final years, in my opinion until the final release of KDE 4.14, the last of KDE4-series releases, that things actually got stable enough to consider good enough for daily use. That means, stable enough to do things without constant fear of something crashing or getting stuck out of nowhere. That is six years of development on massive scale. Revealing of the massive scale of everything was the dependencies which came with KDE applications. If a GNOME user decided to install a KDE application, such as Kate, a great text-editor, in a system "untainted" by KDE, he better prepare to pull 200MB of dependencies with it. This led to strict separation followed by many users. Even if KDE application was way better than GTK alternative, it was wise to take the alternative. I remember showing my father how to install things from Ubuntu Software Centre, and he clicked Gwenview the image viewer before I had chance to explain. There we waited, as otherwise small image viewer downloaded for minutes on the poor internet connection. "Why is this taking so long?" "Ummm... dad it's practically installing another desktop system now as well lol :D".
As if that wasn't enough, part of the intended core functionality was essentially lost, because it worked so badly that many users opted to switch it off entirely. I'm talking about the duo of Strigi, the file indexer, and Akonadi, the PIM management system. Strigi was so demanding on resources and initially was not limited in any way on the resource usage, that it could bring even a desktop system capable of running Crysis on knees. There was for example a bug in PDF content indexing, where Strigi aimlessly tried to index content it couldn't understand. A fast hack piping PDF to text format to be indexed was deviced, but unsurprisingly it didn't work too well either. Slowly KDE became a system hacked together, only adding to code burden. What was supposed to be an elegant architecture became a shoddy patchwork very rapidly out of nescessity. This in turn made the code practically unmaintainable. It is telling, that entering generic search term such as "desktop" into the bugtracker would tell, that Bugzilla can't display so many results. When all else started failing, the KDE developers made a rather drastic decision around 4.13 release to swap Strigi with more lightweight Baloo file indexer. The semantic desktop that developers had envisioned never saw daylight in working condition.
The other issues past the system critical dysfunctionality were in the usability and user interaction. Sometimes they went on a deep level, such as unwillingness of developers to implelent a proper pam-auth and instead sticking to KWallet system, which in theory was more secure, but got so much in the way of daily use, that disabling it by leaving it without password - that is, storing all passwords and secrets unencrypted - became a common recommendation for those many who found it nuisance. For those who never used KDE, imagine opening your mail application. That would require you to give your user password. Or connecting to previously known WLAN, that would require giving user password as well. Or storing a new one, because that would again require opening the wallet. Keyring system that has been in use in every other system from OS X to GNOME to even LXDE was not there. Keyrings are opened transparently, assuming user has managed to log in the system. Rest of the time keyring is encrypted. Again, change happened very late to the lifecycle of KDE4, with experimental pam-auth being implemented in 4.13.
Usability problems didn't end there. The system got a reputation of being laggy. This was technically not the case. It was just that for some reason, Plasma designers decided that having a persistent laggy animation almost everywhere was a good thing. For example, opening the Plasma menu and hovering mouse cursor over menu items had the hover-over animation lagging behind mouse movements. This lag-effect also was in the taskbar, in krunner results and in kickoff menu. The user didn't get visual cue instantly. Changing animation speeds didn't help either. It felt boggy and heavy, despite the entire desktop with full services enabled and entire klibs preloaded used just wee bit over 200MB of RAM. Partial improvement didn't happen until the very last release of 4.14, when taskbar became responsive out of blue as a minor enchantment.
The design in itself of the KDE 4-series was consistently ugly as sin, both inside and outside. It was common wisdom that after installing KDE, one should reserve one evening to set up everything. I developed such a routine that I did it in less than a hour post-install. For sake of writing it down for the first time and enshrine for future generations: swap Oxygen deco to Plastik, disable bunch of transparency effects, make animations near-instant, change colour scheme to my own Aava, set gradients to zero, set up bunch of shortcuts like quick tiling with meta+arrows, kick off Kickoff launcher and replace it with Homerun, swap Air plasma theme to Oxygen, set mouse cursor to Zion, change how toolbar works by setting it to sort manually, disable "helpful tips", change window placement rules to cascading from "smart", delete all inevitable dupes from application menu, set window buttons to: window_menu,keep_above,min,max,close, set mousewheel over titlebar to shade window, hack ibus to integrate properly, disable system sounds, disable startups splash screen, tweak tray to be more relevant. That should do it! It would be much easier to make a script for this all like I did for GNOME3, but for some odd reason that was not possible. Or maybe it was. But there was no such thing as gsettings is for GNOME3 as far as I am aware.
Granted, there was a massive amount of development that needed to happen in order to even make KDE SC happen. The vision proved too much to accomplish. It ruined the reputation of the once-dominant desktop environment and made a system filled with brilliant innovations and many industry firsts a running gag within Linux community. This was a tragedy of grand scale, taking into account the size of willing developers struggling in the codebase and users trying over and over if the system is usable, because it promised so much good from day one. Thankfully, the new KDE 5-series or "Plasma 5 / Frameworks 5 by KDE community" as they insist on calling the entirety, has abandoned the monolithic thinking and embraced a more modular architecture and development model. Now the framework libraries, desktop and applications are separately developed entities. Previously largely singular kdelibs have been made smaller, more manageable pieces. There is no longer any drive to release everything at once. This makes dependency footprint of applications smaller, and pinpointing of bugs easier.
As I am now writing this in KDE 5 made of frameworks version 5.9.0 and Plasma 5.3, it is already obvious that the project has made a great decision. Plasma 5-series is just about year old now counting from 5.0 release, with 5.2 being the first release that got good-to-go for daily use thumbs-up from developers. All the past issues with gross instability, glitchiness, usability errors and design seem to have been fixed. In fact, this desktop is the best one I have ever used in my life, and certainly the most beautiful - by default. The way forward can only make this better still, as the few remaining glitches and incompatibilities are ironed out, and this time hopefully for good once they are squashed for the first time. In the end, experiences of the past seven years seem to have paid off and the same mistakes are now actively avoided. The only question is: was doing all those mistakes for so long really necessary?