Edit: Never mind. A Google search told me that they were coded out as they would bleed through walls. This created balance issues in Multiplayer and Counter-Strike (You could see enemies were behind walls and in vents). Therefore, I'm closing the Issue.
Nothing extracted yet.
The retail Half-Life had the option to enable Shadows with the r_shadows 1 cvar. This is disabled in the Linux/Steam version. If I type it in the console I get:
"Unknown command: r_shadows"
It would be nice to to have it back.