Представлен новый демон печати для Linux — printerd

«The reasons for accepting only PDF are that PDF has a better model for shuffling pages around: each page is fully described separately from the others, unlike can often be the case in PostScript. This is important for printing only selected pages, or for putting several pages on a side (number-up). Applications generally produce PDF output for printing these days, so conversions from PostScript to PDF in the first place should be minimal.

There are several problems printerd aims to solve. Having an asynchronous client API is a start, and implementing the spooler as a D-Bus service does this as D-Bus automatically provides asynchronous client communications — this makes it easier to program UIs such as the print dialog in such a way that they do not block.

Another advantage printerd offers is a coherent security policy incorporating polkit. CUPS provides its own security policy mechanism, but the polkit mechanism is better suited to providing desktop integration. The way this is solved with CUPS is to provide an alternative security mechanism using polkit (cups-pk-helper), and this effectively bypasses the regular CUPS security policy. The result is that the two policy mechanisms are side by side, and if one prevents you doing what you want then you get to try the other.

In contrast, printerd’s only interface is D-Bus. It uses polkit to authenticate operations. If extra security policy is added in future that cannot be expressed using polkit (for instance, printer-specific policy rules) that extra policy layer will be in addition to polkit, not an alternative.

One more benefit of printerd is the idea of splitting the IPP server from the local spooler. Currently printerd only spools files and does not provide IPP services. The idea is that an IPP server can be implemented on top of printerd, using its D-Bus client API. That way, systems that want to print to local printers but are not interested in sharing those printers on the network don’t even have to run the IPP server. In fact, as printerd is an activatable system service, the spooler itself won’t even be running unless there is something for it to do.»

(комментарий Tim Waugh)

Ага, промежуточная конверсия сильно повысит скорость и надежность всего этого добра. Кто пользовался ps2pdf знает какие перлы бывают, например с русскими буквами если со шрифтом какой-то косяк. А поскольку программы все равно выдавать будут постскрипт (ибо стандарт), то добрый день глюки.