Fork

In  engineering, a project fork happens when developers take a copy of source code from a specific software package, and then start independent on it, thus creating a distinct piece of 'new' software.

The term  is also used in the 'wikisphere'. For instance, the above text was forked from the English Wikipedia wiki site! Most free content licenses allow people to copy material in part or whole; to create their own separate versions of that content: be it a cultural work, a piece of media, software, or some intellectual pursuit.

Sometimes, forking results in fragmentation, whereby two separate wiki communities have overlapping but divergent goals. There are strengths and weaknesses to this. On the one hand, different communities can meet different needs, and problem-solve in new ways. This also keeps one cultural work from being dominated or controlled by a single individual or small subset of people. On the other hand, fragmentation can create redundancy, and confusion amongst people.

Wiki forking typically starts as mirroring, which is a similar concept; where one wiki site hosts identical content to another wiki site.

Wiki forking vs. wiki mirroring
A mirror wiki site could, or may also be described as an archive. It duplicates or re-uses content originated elsewhere (hopefully, with proper attribution, and respecting its original license(s)), but a wiki mirror normally, is not an originator of new content.

A wiki fork creates an entirely new second project (sometimes, though not always, with an identical wiki site name); the wiki fork uses a common set of content as a starting point. As the new wiki fork project matures, it builds a (new) community, and creates its own new, unique content, and ultimately its own new identity.

In the global 'wikisphere', the most significant fork was the creation of Wikivoyage. Wikivoyage started as a wholly independent fork of the earlier Wikitravel. The Wikivoyage fork was seeded, and gained significant traction, after the original (private) owners of Wikitravel latterly sold it to Internet Brands, Inc. (a highly commercial, 'for profit' company), which then had the result of alienating the original Wikitravel community (whom like most open content wiki editors, were all unpaid volunteers).

Conversely, the many various sites which merely provide an 'archived' copy of English Wikipedia content online (such as the NationMaster Encyclopedia) without originating new content are mirrors.

On wiki farms
Forking is common on Wikia (now known as Fandom), usually because of its forced skin changes, poor community support, global blocking, enforced social features, and a bombarding plethora of objectional on-screen advertising (including video adverts); and also because independent hosting is more versatile, and more controllable. Where forking occurs, the abandoned Wikia version of the site; invariably left open and frequently dormant, is commonly referred to as the 'spoon'.

Forked wiki articles on WikiIndex
From the founding outset of WikiIndex, the long-term goal has been to have an article entry page; and therefore an infobox; for ALL wiki sites, even dead and / or dormant wiki sites. Forked wiki sites are to be treated with exactly the same ethos; therefore, WikiIndex has a specific method of dealing with forked wiki. Fundamentally, a forked wiki site article (and also any wiki engine forks) should each have their own separate article page, with their own infobox and size template. The two separate wiki site article pages should be annotated at the top of their respective pages with a standard 'hatnote', specifically using template:For; this will give the reader of the article here on WikiIndex salient information, along with the required wikilink, to either the original (spoon) wiki site, or its subsequent forked wiki site.

Mirrored wiki sites may be treated different to forked wiki sites, in that both wiki sites (if both remain active) will eventually contain differing content, and may ultimately form differing identities. In these instances, we would have two (or more, for multiple mirrors) separate page articles here on WikiIndex. Again, just like the forked examples, a 'hatnote' template should be used on all article pages relevant to any mirrors, and the originating wiki site article.