The meshfree MEGA code (Meshfree Explicit Galerkin Analysis code) I've built from the ground up since coming to Penn State is up and running with (nearly) state-of the art in RKPM.
Here's a demo problem. Quasi-linear Reproducing Kernel Particle Method (RKPM) [1-3] with Naturally Stabilized Nodal Integration (NSNI)  for slope stability analysis. Soil is modeled with Drucker-Prager with tension cut-off.
Variationally Consistent Integration (VCI)  to be added soon.
 Liu, Wing Kam, Sukky Jun, and Yi Fei Zhang. "Reproducing kernel particle methods." International journal for numerical methods in fluids 20.8‐9 (1995): 1081-1106.
 Chen, Jiun-Shyan, et al. "Reproducing kernel particle methods for large deformation analysis of non-linear structures." Computer methods in applied mechanics and engineering 139.1-4 (1996): 195-227.
 Yreux, Edouard, and Jiun‐Shyan Chen. "A quasi‐linear reproducing kernel particle method." International Journal for Numerical Methods in Engineering 109.7 (2017): 1045-1064.
 Hillman, Michael, and Jiun‐Shyan Chen. "An accelerated, convergent, and stable nodal integration in Galerkin meshfree methods for linear and nonlinear mechanics." International Journal for Numerical Methods in Engineering 107.7 (2016): 603-630.
 Chen, Jiun‐Shyan, Michael Hillman, and Marcus Rüter. "An arbitrary order variationally consistent integration for Galerkin meshfree methods." International Journal for Numerical Methods in Engineering 95.5 (2013): 387-418.