Based on algorithms published in:
Meade, B. J. (2007), Algorithms for the calculation of exact displacements, strains, and stresses for triangular dislocation elements in a uniform elastic half space, Computers and Geosciences, 33, 1064–1075, doi:10.1016/j.cageo.2006.12.003.
triinv uses tridisl as a submodule. To clone triinv, run
$ git clone --recursive https://github.com/jploveless/triinv.git