This release uses an updated version of opensim-core that includes SmoothSphereHalfSpaceForce, which has now been removed from the Moco codebase. The interface to this class has been updated to use OpenSim’s ContactSphere and ContactHalfSpace classes, so your models must be updated in order to continue using this component. You can refer to the gait model included with example2DWalking for the correct XML syntax and view a file diff of the changes here: https://github.com/opensim-org/opensim-moco/commit/ccd39f82acba5f23ebc3423eb40d2197d6d41d8b#diff-eb627df1f2a265a84a30b7c6b4f92999 Contact tracking was added as an option to example2Dwalking, and MocoContactTrackingGoal was updated to support contact spheres distributed across multiple bodies. MocoControlTrackingGoal was updated to more easily associate controls to reference data, as demonstrated by a new electromyography tracking option added to exampleMocoInverse. A “projection” setting was added to MocoFrameDistanceConstraint to provide more flexibility in posing this constraint. DeGrooteFregly2016Muscle's passive force multiplier now has a stiffness parameter. To support this change, the curve was tweaked slightly. This may have a minor effect on solutions relying on passive fiber forces. The maximum difference between the new and old passive force-length curves is 0.07 (unitless). Finally, we’ve included various bug fixes in this release: - Fixed a bug where MocoPeriodicityGoal incorrectly specified control constraints - Fixed an error that occurs when using ModOpRemoveMuscles - Fixed some default pelvis and lumbar parameters in createPeriodicTrajectory() - Added some missing MATLAB and Python commands to the bindings More details about this release are in the CHANGELOG.md file.