One of our favorites is the CosmoPlayer, which is now available in version 2.1. You can try viewing the Virtual Orion file in your web browser and see if a VRML browser is installed. Many versions of Netscape have a VRML browser bundled with them. If one is not installed, you will possibly see a screen full of code, which is the file containing the display data for Virtual Orion.
Many browsers require high end equipment, current version operating systems, and lots of memory.
Determine if your system fits the profile before downloading. Although the interface varies from browser to browser, the functions are generally the same. It takes some experimentation to see the effect of each type of motion. CosmoPlayer has a lot of buttons, but little explanation of what they do. The basic functions are simple, you just need to get oriented.