We describe the implementation of algorithms to construct and maintain threedimensional dynamic Delaunay triangulations with kinetic vertices using a threesimplex data structure. The code is capable of constructing the geometric dual, the Voronoi or Dirichlet tessellation. Initially, a given list of points is triangulated. Time evolution of the triangulation is not only governed by kinetic vertices but also by a changing number of vertices. We use three-dimensional simplex flip algorithms, a stochastic visibility walk algorithm for point location and in addition, we propose a new simple method of deleting vertices from an existing three-dimensional Delaunay triangulation while maintaining the Delaunay property. The dual Dirichlet tessellation can be used to solve differential equations on an irregular grid, to define partitions in cell tissue simulations, for collision detection etc.Key words: Delaunay triangulation, Dirichlet, Voronoi, flips, point location, vertex deletion, kinetic algorithm, dynamic algorithmIn nearly all aspects of science nowadays simulations of discrete objects underlying different interactions play a very important role. Such an interaction for example could be mediated by colliding grains of sand in an hourglass or -more abstract -the neighborhood question of influence regions. One general method to represent possible two-body interactions within a system of N objects is given by a network which can be described by an N × N adjacency matrix ν, with its matrix elements ν ij = ν ji (undirected graph) representing the interaction between the objects i and j. However, for most realistic systems the graph defined this way is not practical if one remembers that the typical size of a system of atoms in chemistry can be O (10 23 ), the human body consists of O (10 18 ) cells and even simple systems such as a grain-filled hourglass