Ladislav Lhotka at cz.nic (which, from what I understand, is the administrator of the .cz TLD) have published a translation of The Performance of Open Source Applications: “Výkonnost Open Source Aplikací”.
On their site you can read an overview of the book, download links for the book and many others, or go straight for the pdf version.
I wish I could explain to you how cool it is that this book got translated by people I don’t know on the internet without any contact from them. Creative Commons has always seemed like a great way to license your works, especially community efforts like POSA, but I don’t often see it in action. Thank you Ladislav and friends!