In technology, a walled garden is a closed ecosystem, analogous to the traditional horticultural meaning. Walled gardens are common in communities that cannot tolerate dissent or which have a strong resistance to outside input.
The subject is relevant to the study of cults, where it is common to pressure adherents to only associate with fellow cult members and to cut off contact with dissenting family members and others who might be sources of differing views than the cult's teachings; to propaganda and governments which discourage or make it illegal to access news sources outside government-approved channels; and to pseudosciences which cite only to each others' non-peer-reviewed journals.
Cold fusion advocacy is a classic walled garden: a small number of individuals running their own conferences, their own websites and journals, talking to each other, but rarely if ever engaging the mainstream at all. WikiWikiWeb summarises this neatly as "isolated little worlds".
The Lyndon LaRouche movement and its front groups are another example. LaRouche publications cite almost exclusively other LaRouche publications as well as Lyndon LaRouche's writings and speeches, creating an ideology which is internally consistent to its adherents even though it contains many views which are simply absurd to the outside world.
 See also
- Walled Garden (technology) on some random website somewhere.