Picapica lets you compare a text to the entire Wikipedia. In seconds, it searches for passages of reused text, extracts them, and displays them in a convenient form.
Picapica currently supports analyses in 10 languages: English, German, Spanish, French, Italian, Dutch, Swedish, Portuguese, Catalan, and Basque.
There's no magic in Picapica, but a number of state-of-the-art algorithms. Don't hesitate to take a look under the hood.
Picapica is in public beta, and still subject to R&D. It's not perfect, but we're working hard to improve. Let us know of any errors you observe!