to the program, but only a specific number at the same time. Another license model is licensing per dongle, which allows the owner of the dongle to use the program on any computer. Licensing per server, CPU or points, regardless the number of users, is common practice, as well as site or company licenses. Sometimes one can choose between perpetual (permanent) and annual license. For perpetual licenses, one year of maintenance is often required, but maintenance (subscription) renewals are discounted. For annual licenses, there is no renewal; a new license must be purchased after expiration. Licensing can be host/client (or guest), mailbox, IP address, domain etc., depending on how the program is used. Additional users are inter alia licensed per extension pack (e.g. up to 99 users), which includes the base pack (e.g. 5 users). Some programs are modular, so one will have to buy a base product before they can use other modules. Software licensing often also includes maintenance. This, usually with a term of one year, is either included or optional, but must often be bought with the software. The maintenance agreement (contract) typically contains a clause that allows the licensee to receive minor updates (V.1.1 => 1.2), and sometimes major updates (V.1.2 => 2.0). This option is usually called update insurance or upgrade assurance. For a major update, the customer has to buy an upgrade, if it is not included in the maintenance agreement. For a maintenance renewal, some manufacturers charge a reinstatement (reinstallment) fee retroactively per month, in the event that the current maintenance has expired. Maintenance sometimes includes technical support. When it does, the level of technical support, which are commonly named gold, silver and bronze, can vary depending on the communication method (i.e. e-mail versus telephone support), availability (e.g. 5x8, 5 days a week, 8 hours a day) and reaction time (e.g. three hours). Support is also licensed per incident as an incident pack (e.g. five support incidents per year). Many manufacturers offer special conditions for schools and government agencies (EDU/GOV license). Migration from another product (crossgrade), even from a different manufacturer (competitive upgrade) is offered. Free and open-source software licenses There are several organizations in the FOSS domain who give out guidelines and definitions regarding software licenses. Free Software Foundation maintains non-exhaustive lists of software licenses following their The Free Software Definition and licenses which the FSF considers non-free for various reasons. The