However, the visual editor soon becomes awkward to use and thus leads naturally into using a scripting language instead. I started with XSLT expecting to move quickly into XQuery, but I've been surprised to find how much can be done, especially with XSLT2.0. For a transformation engine, I've set up a service (using Saxon8 via XQuery on eXist-db). This has allowed us to implement most of the yahoo pipes we'd written and also searches over an XML file with a single script containing a form and the search results. More..
Although many of the steps in a Yahoo pipeline can be handled within a single XSLT script, some of the processing I want to demonstrate involves processing HTML pages which are not XHTML, so I needed a tidy service too, and to be able to pipeline them together.
So... I need a pipeline language, a way of visualizing the pipeline and an engine to execute the pipeline. Naturally I started to write my own, based mainly on XPL which Eric Bruchez introduced me to at XML Prague. A tentative first step using an XQuery script is described in an XQuery WikiBook article.
Of course this is fine as play but I need to join the real world of pipeline languages. I suppose the main contenders are :