They have been drawn up since 1984 by an international working group of the inter-governmental organization UNIDROIT, and they were ratified by its Council representing 64 governments of member states.
The UNIDROIT Principles were first released in 1994, with enlarged editions published in 2004, 2010, and most recently in 2016 (including issues related to long-term contracts).
Established with an international mind-set, they address many issues on which national legislators do not concentrate, such as foreign-currency set-off or hardship.
Practitioners who use the principles describe them as a state-of-the art tool which is particularly useful when parties from different legal systems desire to agree on a neutral contractual regime.
International law firm networks have an increasing number of committees concentrating on promoting the use of the UNIDROIT Principles in practice (e.g. the International Bar Association; Primerus Society of Law Firms).