trussDFEM ("trusty FEM") lets you compute and plot truss deformation using FEM methods.
Build a truss using bearings, nodes, elements and loads, and compute and plot the truss deformation. Not half as fun as it sounds but it looks pretty cool.
Here's the results and plot for truss 1 (option #8 in the menu). Select 8, then 7 in the menu to compute:
