Keep It Simple, Stupid (comma optional), often abbreviated as KISS, is partly a (useful) catchphrase and partly a way of life. It is originates from the US military in the '60s, and is attributed to aircraft engineer Kelly Johnson. The fundamental idea is that, when designing something, unneeded complexity should be avoided at all costs, because the simplicity will be the most useful aspect when you need something done.

Today KISS can be found on, in, and around all sorts of media: posters, slogans, clothing, books, disgruntled advice from experienced coworkers. My personal favourite is its use in the book Vertical Run by Joseph Garber: it perpetuates the air of practical cunning around the protagonist, and I am a sucker for macho ex-military badasses.

There are many examples of KISS at work:

- Occam's Razor, a scientific and philosophical principle stating that simpler theories are better unless one has more explanatory power
- Less is more, another popular phrase, famously used by 20th century minimalist architect Ludwig Mies van der Rohe
- Minimalism itself, a design movement advocating only the barest essentials
- Brevity is the soul of wit, a famous Shakespearean aphorism
- Simple English Wikipedia, a free encyclopedia written using a simple subset of English's vocabulary
- This node, proudly kept simple