How can I use c++11 when programming the Arduino? I would be fine using either the Arduino IDE or another environment. I am most interested in the core language
If you need more control and better IDE, I recommend using Sloeber Plugin for Eclipse or the Sloeber IDE itself. Creating more complicated code is much easier using this IDE. It also allows to add flags to compiler (c, c++ and linker). So to customize the compile, just right click on project and select Properties. In the Properties window, select Arduino->Compiler Option. This way you can add options to your build.