- The document discusses the Orfeo ToolBox (OTB) users meeting and hackfest in 2015, specifically regarding third party dependencies and the SuperBuild system. - It outlines how OTB has reduced the number of third party dependencies and now uses a SuperBuild system to download, compile, and install dependencies at build time rather than including their source code directly. - The SuperBuild system allows OTB to be built on any platform with just a compiler and CMake by handling all dependency installation, and provides consistent versions of dependencies across platforms.