EPQ is the Electron Probe Quantification library, the foundation on which NIST DTSA-II and NIST Graf are constructed.
EQP is a Java library that simulates, quantifies and plans energy dispersive X-ray spectrometry measurements.
Documentation for DTSA-II and EPQ can be found here - https://cstl.nist.gov/div837/837.02/epq/dtsa2/index.html