QUEELS: Software to calculate the energy loss processes in TEELS, REELS, XPS and AES including effects of the core hole

We present the user-friendly and freely available software package QUEELS (QUantitative analysis of Electron Energy Losses at Surfaces) which allows to calculate effective inelastic scattering cross sections within dielectric response description, for swift electrons traveling nearby surfaces in several environments. briefly describe underlying theoretical models illustrate its use evaluate distribution energy losses taking place electron spectroscopies like TEELS, XPS, AES, REELS are widely used material analysis. This includes intrinsic excitations due core hole XPS AES.