The highlight of the release is the implementation of the Lower-Interface Elements for both the small deformation process (M) and hydro-mechanics process (HM) allowing fractures to be incorporated in the solution domain. For the liquid flow and two-phase flow processes several material models for the fluids pressure, density, permeability, and viscosity were added. Features: Implementation of hydro-mechanics (HM) with LIE. #1537-#1541 Implementation of small deformation (M) with LIE. #1452 Fracture constitutive models. #1434 Hydro-Mechanics process. #1508 First version of monolithic hydro-thermal process implementation with Boussinesq approximation using constant viscosity. #1534 Two phase flow process with pp model implementation. #1530 Richards flow process implementation. #1473 Liquid process. #1468 Classes for relative permeability models. #1531 Classes for capillary models. #1517, #1578 Ehlers single-surface yield function constitutive relation model. #1556 Support scaling, GMRES, and Pardiso in Eigen linear solvers. #1509 #1510 Piecewise linear Monotonic curve and a generic curve parser. #1529 Support searching boundary nodes in MeshLib::NodeSearch. #1459 Support specifying the shape function order in process variables. #1503 Command line option --unbuffered-std-out to deactivate buffer for standard output. #1514 CMake option OGS_FATAL_ABORT for debugging. #1432 Set the default OGS_LOG_LEVEL to debug in release builds. #1522 Add integration order in input files. #1464 Utilities New utilities: createQuadraticMesh #1500 convertToLinearMesh #1554 postLIE #1555 New features: extend NodeReordering to correct ordering of nonlinear nodes #1519 Infrastructure: Ctest now works on Windows too by removing time-wrappers. #1480 Moved to public Jenkins instance at jenkins.opengeosys.org. #1505 Doxygen warnings parser in Jenkins will mark a build as unstable if there are Doxygen warnings. #1585 Benchmarking on Jenkins now saves the standard output into a file for each test. #1528 Fixes: Fix LocalToGlobalIndexMap with mutliple variables and with multiple componets. #1433 #1440 Fix PropertyVector<T*> for multi-component case. #1441 Fix checking IDs of nonlinear nodes. #1495 Fix incorrect use of getNumberOfBaseNodes(). #1515 Fix computing sparsity pattern for mixed shape function order cases. #1548 Fix that iterations and residuals were not printed when Eigen linear solver fails. #1499 Fix all of the Doxygen warnings in the code. #1569 #1573 Fix all of the input file/keyword documentation and its generation.