Quick test 'freeCAD': 
Make sure that the example assemblies (*.asm) are in the directory of the image. 
Click File/Open/Assembly/ to get list of example assemblies. 
Choose one, say, fourbar.asm 
Click View/Tilt Rotate/ to center the model.  Drag the handles to tilt and rotate the 3D assembly. 
Click Simulation/Animation/ to get the animation dialog. Click Play to start animation. 
You can click any View menu item and drag handles, even during animation. 
Please report any problems to 
A-S Koh 
askoh@askoh.com

Quick start: 
Click Explain/Quick Start/ to learn how to build a model from scratch. Together, the tutorials demonstrate the available features in 'freeCAD'.