datapile uses Play
Play is a central framework/component/library (not sure what to call things these days) in Scala. We <3 Scala, and therefore we <3 Play.
Play is on of several frameworks we are prototyping and vetting for various public-facing websites, and may ultimately be the framework behind the main datapile.io website.
Perljobs.Ru uses Mojolicious
Web part is fully written on top of Mojolicious. Thanks Sebastian Riedel and all the contributors for the great framework!
Веб бэкенд написан полностью на Mojolicious. Спасибо Риделю и всем участникам за этот фреймворк!
elo80ka uses Play
I used Play to build a configuration UI for the service, which let you create and manage the menus (a hierarchical tree of options and actions).