It's the "run command" dialog of KDE, it was already available for KDE 3.5.x, but it got a new appeareance and functions, now it's completely plugin based, and shares your plasmoid theme. I already showed a screenshot of it in the Plasma Article, but here is another one in case you forgot about it:
Quite simple, yet good looking :) If you start writing, you'll get different options based on what you wrote:
However, as I told you, it's completely plugin based, let's have a look at the configuration dialog:
And it gives you fast access to the running processes:
Easy, isn't it? Now I'm going to showcast every plugin :)
As you probably noticed, I'm not using oxygen this time... I'm using bespin.
Find Applications: Based on general usage criterias
Bookmarks: It can search in your bookmarks too, just write the site name, description, or address and you'll get fast access to it :)
Calculator: ... kinda obvious, like the previous one XD:
File Manager Bookmarks: No, that isn't my home folder, it's my windows user folder
It can look for contacts, check your spelling, sessions management (shutdown, reboot, log out, etc) and open konqueror, kate and konsole sessions, but I kinda believe that this article has already became a little bit repetitive XD.
Next week: Dragon Player