KDE 4.0 is out, so I installed the release packages and tried to conduct an ordinary day with them. I read mail, edited code, moved files and used a browser. By mid-afternoon I had also restarted Plasma and learned several new ways not to configure a panel.

My naive expectation was that the version number marked a direct successor to my mature KDE 3 desktop. I copied over habits even when settings could not be copied: right-click here, drag this there, expect every old control in approximately the old location. That turns 4.0 into a scavenger hunt it cannot win.

The candid result is mixed. Dolphin is quick and pleasantly focused for local file work. Okular opens the documents I need and gives them a consistent interface. KWin without ambitious effects is stable on this machine. Oxygen makes the applications look related, though a few small icons still require concentration.

Memory use is not alarmingly different in this limited test, although comparing young and mature sessions by one number would prove very little.

Plasma is the weak centre. Basic panel and desktop behavior works, but arranging widgets is awkward, configuration is thin, and occasional crashes make the entire workspace feel less reliable than the applications deserve. Some conveniences from KDE 3 simply are not present. Hardware integration and notifications also have visible seams.

This happens because 4.0 is not only a set of ported programs. Qt 4, new libraries, a new desktop shell, new hardware plumbing and revised applications all meet at once. The architecture creates room for future improvement, but users interact with current code, not future room.

I can use KDE 4.0 for testing and for a limited second session. I cannot recommend replacing a carefully tuned KDE 3 work environment yet. That is not a condemnation of the project; it is a description of my desk today.

The practical conclusion is to install with a clean user, keep important work elsewhere, and report narrow failures. KDE 4.0 shows enough of the intended system to be exciting, but the release number should not be mistaken for accumulated polish. Zero is a wonderfully round number. It is not a maturity metric.