Today is tax day in the Netherlands: time to get these return forms in and hope for a bit of cash from the government. Two years ago the state started demanding that business owners start filing their reports electronically, using a Windows and Mac only tool based on Adobe’s PDF. Last year they got smarter and developed their own tool, which works on Windows, Mac and GNU/Linux. The secret ingredient? Open Source libraries. Specifically: gSOAP, OpenSSL, wxWidgets, GTK+, ZLIB, Independent JPEG Group components, Autopackage, and NSIS.