For a common class of two-dimensional (2D) mechanisms called 1-dof tree-decomposable linkages , we present a software package, CayMos, which uses new theoretical results from Sitharam and Wang [2014] and Sitharam et al. [2011a, 2011b] to implement efficient algorithmic solutions for (a) meaningfully representing and visualizing the connected components in the Euclidean realization space; (b) finding a path of continuous motion between two realizations in the same connected component, with or without restricting the realization type (sometimes called orientation type); and (c) finding two “closest” realizations in different connected components.