To build from source for Linux or other UNIX/UNIX-like systems, it is generally sufficient to download just the source qpdf-.tar.gz file. For Windows, there are several additional files that you might want to download. * qpdf--bin-mingw.zip If you just want to use the qpdf commandline program or use the qpdf DLL's C-language interface, you can download this file. You can also download this version if you are using MINGW's gcc 4.4 and want to program using the C++ interface. * qpdf--bin-msvc.zip If you want to program using qpdf's C++ interface and you are using Microsoft Visual C++ .NET 2008 (VC9), you can download this file. * qpdf-external-libs-bin.zip If you want to build qpdf for Windows yourself with either MINGW's gcc 4.4 or VC9, you can download this file and extract it inside the qpdf source distribution. Please refer to README.windows in the qpdf source distribution for additional details. * qpdf-external-libs-src.zip If you want to build the external libraries on your own (for Windows or anything else), you can download this archive. In addition to including unmodified distributions of pcre and zlib, it includes a README file and some scripts to help you build them for Windows.