The modifiers on the Modifiers tab are: Bend, Taper, Skew, Twist, Stretch, Noise, Wave, Melt, Spherify, Ripple, FFD Box, FFD Cylinder, XForm, Flex, Morpher, Skin, Displace, Optimize, Smooth, Cap Holes, Linked XForm, Push, Vertex Paint, MeshSmooth, Volume Select, Mesh Select, Edit Mesh, Edit Patch, Edit Spline, Spline Select, UVW Map, Unwrap UVW, and Material ID.
When there are no objects in a scene to be modified, the buttons are greyed out, as above.
