Mouse Operation 

    Silo has a completely customizable mouse, which is setup using the Mouse Setup dialog.  You can save and load any number of different setups, in case, for example, you wanted to try the setup of another artist you saw on the internet.  The default setup is summarized below, using the notation LMB, MMB, and RMB for left, middle, and right mouse buttons, respectively.  For all selection operations, you can drag to perform an area select or paint selection, depending on which of those two modes is active.  The difference between Select Thru and Select Visible is that with Select Thru all of the geometry that lies beneath the selection area will be selected, while with Select Visible, only the compnents you can see are selected.

Default:
LMB - Select Visible New
MMB - Select Thru New
RMB - Right-Click Menu, also button info (when over a button), and ends tools when a tool is active.

Alt+LMB - rotate view while dragging
Alt+MMB - pan view while dragging
Alt+RMB or Alt+LMB+MMB - zoom view while dragging (left to right)

Shift+LMB - Select Visible Add
Shift+MMB - Select Thru Add
Ctrl+Shift+LMB - Select Visible Complement
Ctrl+Shift+MMB - Select Thru Complement
Alt+Shift+LMB - Select Visible Subtract
Alt+Shift+MMB - Select Thru Subtract

Scroll - Soft Selection Radius Up/Down
Ctrl+Scroll - Soft Selection Falloff Up/Down
Alt+Scroll - Zoom In/Out
Ctrl+Alt+Scroll - Cycle Shading Modes