In computer programming, Big Ball of Mud is a term for a system or computer program that has no real distinguishable architecture. It usually includes more than one of the other anti-patterns. Computer programming (often simply programming) is the craft of implementing one or more interrelated abstract algorithms using a particular programming language to produce a concrete computer program. ... In computer science, anti-patterns are problems that occur frequently in computer programming and that programmers following good practice tend to avoid. ...

The term was popularised in Brian Foote and Joseph Yoder's 1999 paper of the same name, which defines the term thus: 1999 is a common year starting on Friday of the Common Era, and was designated the International Year of Older Persons by the United Nations. ...

"A Big Ball of Mud is a haphazardly structured, sprawling, sloppy, duct-tape-and-baling-wire, spaghetti-code jungle. These systems show unmistakable signs of unregulated growth, and repeated, expedient repair. Information is shared promiscuously among distant elements of the system, often to the point where nearly all the important information becomes global or duplicated. The overall structure of the system may never have been well defined. If it was, it may have eroded beyond recognition. Programmers with a shred of architectural sensibility shun these quagmires. Only those who are unconcerned about architecture, and, perhaps, are comfortable with the inertia of the day-to-day chore of patching the holes in these failing dikes, are content to work on such systems."

Big Ball of Mud systems were usually developed over a period of time with different individuals working on various pieces and parts. Expediency plays a major role. Systems developed by people with no formal computer architecture or programming training also often fall into this pattern. A roll of duct tape Duct tape, originally known as duck tape, is a strong, fabric-based, multi-purpose adhesive tape, usually silver in color, although many other colors, including transparent, are also available, and is usually 2 inches (50 mm) wide. ... A plate of spaghetti looks twisted and tangled, which is where the name for spaghetti code comes from. ...

Foote and Yoder do not universally condemn Big Ball of Mud programming, pointing out that this pattern is most prevalent because it works — at least for the moment. However, programs of this pattern become maintenance nightmares.

Programmers in control of a Big ball of mud project are strongly encouraged to study it and to understand what it accomplishes and use this as a loose basis for a formal set of requirements for the new well architected system that would be developed to replace the former. Technology shifts (client-server to web-based, file-based to database-based, etc.) can provide good reasons to start over from scratch. Client/Server is a network application architecture which separates the client (usually the graphical user interface) from the server. ... A file in a computer system is a stream (sequence) of bits stored as a single unit, typically in a file system on disk or magnetic tape. ... A database is a collection of information stored in a computer in a systematic way, such that a computer program can consult it to answer questions. ...

External link

• Big Ball of Mud (http://www.laputan.org/mud/mud.html) (1999 paper)