[* http://www.avc-cvut.cz/images/flag_gb.gif *] This presentation is in english. Tato přednáška je v angličtině. The XProc XML pipeline language is well on its way to be standardized at W3C. But, exactly, what are XML pipelines good for? And how do they work in practice? In this talk, we attempt to answer these questions by presenting use cases for XML pipelines implemented with XPL, a close cousin of XProc. We show in particular how XML pipelines fill a niche in the constantly evolving web applications ecosystem. Can XML pipelines help deal with multiple web browsers? With REST services? With the plethora of syndication formats such as RSS and Atom? With Ajax? We suggest that the answer is yes in all these cases. We also show how XML pipelines can play a particularly interesting role when used in conjunction with XForms. The talk will feature live demonstrations using open source software.