Version 3 of RunDec and CRunDec

We present new versions of the packages RunDec and CRunDec which can be used for the running and decoupling of the strong coupling constant and quark masses. Furthermore several conversion formulae for heavy quark masses are implemented. The new versions include five-loop corrections of the QCD beta function and four-loop decoupling effects. Furthermore, various relations between the heavy quark mass defined in the $\overline{\rm MS}$ and other short-distance schemes are implemented to next-to-next-to-next-to-leading order. We discuss in detail the improvements and provide several examples which show how RunDec and CRunDec can be used in frequently occurring situations.