Centralismo y dispersionismo
This is an essay. It expresses the opinions and ideas of some MediaWiki.org users, but may not have wide support. Feel free to update this page as needed, or use the discussion page to propose major changes.
Centralism and decentralism are competing approaches for MediaWiki development and administration. There are two levels of centralization: code deployment and distribution for the MediaWiki community as a whole, and for individual wikis. The former is reflected in, for example, the schools of thought concerning integration of extensions into the core. The latter is reflected in, e.g., relative advantages of bots and server-side tools or a decision to hack MediaWiki core.
Centralism makes it possible to impose relatively uniform standards, rather than relying on individual users or system administrators to make needed changes. Uniformity ensures that if the global standard is good, then good standards will be more widely applied. Uniform standards, whether good or bad, also give people assurance as to what they can expect (e.g. from one wiki to the next) and to plan accordingly.
Decentralism allows experimentation by different users and wikis that can result in gathering more and better information about what works best, and thereby speed up progress. It allows individual users and wikis to act relatively quickly on the information they possess, rather than trying to inform a central planner and convince him to adopt and implement their proposed plan. Small experiments can be less costly than large experiments.