Suppose I have a functioning molecular dynamics package for classical MD. I want to extend this code to run path integral MD. I know that a surprisingly small number of new features need to be implemented, but the literature I am aware of is quite formal, where I'd be interested to look at a more algorithmic description of what steps need to be added to the usual integration of Newton's equations in classical MD.
Any references, books or articles, you've seen which fit the description, I'd love to look at. Alternatively, a simple reference implementation would be nice. It's quite easy to find reference implementations of path integral monte carlo, but not as much PIMD.