(SParx for HIgh Resolution Electron microscopy) a tool for cryoEM using statistical resampling to attain quality assessment and result reproducibility. Includes movie frame alignments (movie), CTF estimation of raw electron micrographs (cter), picking/stack creation (window), reproducible 2-D classification (isac), reproducible initial model generation (viper), automatic gold-standard 3-D refinement (meridien), local resolution estimation and filtering (localres), and up to the 3-D sorting of different conformational states based on the statistical 3-D variability of the data (sort3D).