openlicence

Openlicence is a term used to describe licenses that grant broad permissions for the use, modification, and redistribution of a work. It is commonly applied to software, data, and creative content to facilitate reuse, collaboration, and dissemination. An open licence typically allows at least non-exclusive use, with varying requirements such as attribution, share-alike, or not using the work for certain purposes. Some open licences permit commercial use, while others restrict it; the specific terms are defined by each licence.

Open licences are often distinguished from public domain dedication in that they impose defined conditions while still preserving broad access. They also differ from restrictive licenses by prioritizing openness and reuse. Major families of open licences include software licences such as MIT, Apache 2.0, and GNU General Public License (GPL); content licences like Creative Commons licences (for example CC BY and CC BY-SA); and data licences such as CC0 and certain Open Data Commons licences. Each licence combination has implications for redistribution, compatibility, and obligation.

Key considerations include permissive versus copyleft approaches. Permissive licences generally require attribution and include few restrictions on downstream use. Copyleft licences require derivative works to be licensed under the same or a compatible open licence. License compatibility can limit combining works with different terms. Openlicences aim to lower barriers to reuse while balancing rights and obligations, contributing to transparency, innovation, and educational access. The concept emerged from the open-source and open data movements and is widely used by governments, institutions, and individuals.