One of the missing features of KDE 4 compared to KDE 3 was the not longer available KPrinter, a tool to print Postscript documents even out of non-KDE programs.
In KDE 3 KPrinter was responsible for printing of KDE applications, but other programs used it as well: if they had no own printing configuration but the possibility to add a generic command (like lp/lpr) they were often configured to print against the KPrinter command. KPrinter took the printed file and provided the the user a modern and flexible graphical user interface dialog to pick the preferred printer, change the printer configuration and so on.
With the transition to KDE 4 KPrinter vanished in favor of the Qt print dialog options, which worked only for Qt/KDE programs. All other programs outside Qt/KDE which relied on KPrinter as a drop-in command line tool were at a loss.
Now Marco Nelles – a co-worker of mine here at credativ – published KPrinter for KDE 4. As the (German) blog post shows the new Kprinter provides what we already know from the KDE 3 times: a drop in replacement for other command line printing tools but with the usability and flexibility of the KDE printing dialog. The two screenshots of the post give you an idea of the new interface. For example, the new KPrinter offers to scale the pages to various sizes and even print posters.
This development is incredibly useful if you have legacy software or software which does not offer for example a cups interface. It also helps in case you need to print Postscript files with your own applications but do not want to hook on to Cups yourself.
As the blog post mentions, the future of the kprinter code, hosted at Github, is open for everyone to participate. It might be worth a thought for example to extend the code to also process PDFs. If you want to track the development of kprinter you also might want to follow kprinter’s kde-apps page.