Shockwave content is created with Macromedia Director authoring software. You will need to purchase this software in order to utilize Shockwave on your website.
Over 95% of all web browsers do recognize Shockwave content. For those clients which do not, the Shockwave player will need to be installed. For those who do not download and install the player, Shockwave content will be unrecognized.
This is a downfall to Shockwave - it is not supported by all web browsers.