I rarely use lens without using any Prisms so this is slightly out of scope, but I absolutely love both lens-aeson and my own package hexpat-lens for diving deeply into nested data structures. Here's a line from a toy web scraper I wrote a few weeks ago using hexpat-lens. p ^.. _HTML' . to allNodes . traverse . named "a" . traverse . ix "href" . filtered isLocal . to trimSpaces The _HTML' bit is a parser Prism based loosely on lens-aeson's _JSON Prism and allNodes uses lens' built-in generic traversal machinery. Specifically, it's a synonym for universe which uses the Plated instance I wrote since there's an obvious concept of the child of an XML node. You could do it even more lens-ily by using universeOf and passing it a traversal into the children. Anyway, that's all the "extra" stuff used here. The essence of this code is to dive into all of the anchors in a page, pull their href (if it exists), remove any non-local hrefs, and then canonicalize the final string. The (^..) runs the traversal returning a list of the results. The clever part I want to share is the use of ix here enabled by the Ixed instance for UNode which lets me treat the implicit attribute dictionary using the generic lens machinery. Also in XML processing, I've begun to look into the bidirectional programming XML pickler libraries. I'm not sure which will work best for me right now, but by writing a few combinators like `xpWrapIso` I'm able to integrate the entire Iso machinery of lens (of which there is a lot) to bootstrap the parser/printers I'm writing. Hopefully this gives a good, if brief, glimpse into some practical lens usage I've had recently. — Joseph