A Vickrey auction is an auction for any number of (identical) items, where the top bidders win the items (a single item for each of the top bidders) and pay the price set by the highest losing bid. The most common example of a Vickrey auction is the second price sealed bid auction of a single item.
Another example is a fifth-price auction of 4 identical items, with (say) 8 bidders, who give the following bids (from highest to lowest):
In that case, the top four bidders (bidders 3, 1, 5, and 8) would each win one of the items. They would each pay $62.24 for the item, since that is the highest losing bid.
There is currently no online experimental software available for a general Vickrey auction. However, when only one item is for sale, the second-price sealed bid auction is a Vickrey auction. See below for the available second-price sealed bid experimental software: