High Quality Content by WIKIPEDIA articles! In computer programming, SOLID (Single responsibility, Open-closed, Liskov substitution, Interface segregation and Dependency inversion) is a mnemonic acronym introduced by Robert C. Martin in the early 2000s which stands for five basic principles of object-oriented programming and design. The principles when applied together intend to make it more likely that a programmer will create a system that is easy to maintain and extend over time. The principles of SOLID are guidelines that can be applied while working on software to remove code smells by causing the programmer to refactor the software`s source code until it is both legible and extensible. It should be used with test-driven development, and is part of an overall strategy of agile and adaptive programming.