To build FBE you need Visual Studio 2015, Community Edition is suitable. You can try previous versions, but it's untested. Nothing else is required.
To make installer you need to install NSIS Unicode 2.58 or higher. Download inetc plugin and copy unicode version to \Plugins folder of NSIS.
Then build Release|Win32 configuration of FBE twice (at first build ExportHTML project cannot find autogenerated by FBE project fbe.h header, will be fixed later). Build Release|x64 version of FBShell project.
Fist run \Installer\MakeInstaller.bat to copy required files to Installer folder, and after this load MakeInstaller.nsi to NSIS and compile.