A perpetual license allows someone to use software without annual renewals once the cost of the license is paid. Once a user pays the fee, the license can be used until the person no longer needs it.
For example, Oracle offers software licenses for perpetual use, as well as licenses that are good for fewer years at a fraction of the perpetual cost. A four-year license is 60 percent of the perpetual rate, as of September 2014, whereas a two-year license is 35 percent of the cost of a perpetual license.
Mestrelab Research offers a perpetual license for chemistry software with an annual fee to receive updates and technical support. As of September 2014, annual updates are 20 percent of the perpetual license price.