Proof of concept in the context of Technology demonstration

Computer Space is a 1971 space combat arcade video game. Created by Nolan Bushnell and Ted Dabney in partnership as Syzygy Engineering, it was the first arcade video game as well as the first commercially available video game. Computer Space is a derivative of the 1962 computer game Spacewar!, which is possibly the first video game to spread to multiple computer installations. It features a rocket controlled by the player engaged in a missile battle with a pair of hardware-controlled flying saucers set against a starfield background. The goal is to score more hits than the enemy spaceships within a set time period, which awards a free round of gameplay. The game is enclosed in a custom fiberglass cabinet, which Bushnell designed to look futuristic.

Bushnell and Dabney designed the game in 1970–71 to be a coin-operated version of Spacewar!. After the pair were unable to find a way to economically run the game on a minicomputer such as the Data General Nova, they hit upon the idea of instead replacing the central computer with custom-designed hardware created to run just that game. While they were working on an early proof of concept, Bushnell found a manufacturer for the game in Nutting Associates. Working in partnership with Nutting, the pair completed the game and ran their first location test in August 1971, a few months prior to the display of a similar prototype called Galaxy Game, also based on Spacewar!. It was first shown to industry press and distributors at the annual Music Operators of America (MOA) Expo in October. With encouraging initial interest, though mixed responses from distributors, Nutting ordered an initial production run of 1,500 units, anticipating a hit game.

Ivy Mike was the codename given to the first full-scale test of a thermonuclear device, in which a significant fraction of the explosive yield comes from nuclear fusion.Ivy Mike was detonated on November 1, 1952, by the United States on the island of Elugelab in Enewetak Atoll, in the now independent island nation of the Marshall Islands, as part of Operation Ivy. It was the first full test of the Teller–Ulam design, a staged fusion device.

Due to its physical size and fusion fuel type (cryogenic liquid deuterium), the "Mike" device was not suitable for use as a deliverable weapon. It was intended as a "technically conservative" proof of concept experiment to validate the concepts used for multi-megaton detonations.

The Samsung Galaxy Fold is an Android-based foldable smartphone developed by Samsung Electronics. Unveiled on February 20, 2019 alongside the Galaxy S10 series, the Galaxy Buds and the Galaxy Watch Active, it was released globally beginning on September 6, 2019. The device is capable of being folded open like a book to expose a 7.3-inch tablet-sized flexible display, while its front contains a smaller “cover” display, intended for accessing the device without opening it. With the announcement of the Galaxy Z Flip, a foldable in a clamshell form, Samsung's foldable phones were made part of the Galaxy Z series. This also retroactively applies to the Galaxy Fold.

The Galaxy Fold received mixed pre-release reception, with praise for its innovative design, but criticism over the device's durability and longevity, and it was concluded that the Galaxy Fold was a proof of concept device for early adopters rather than a device suited for the mass market. Due to issues with the device's durability and susceptibility to damage, Samsung announced that it would recall the review units and delay the release of the Galaxy Fold indefinitely while it addressed the problems. Samsung officially detailed its design changes in July and released the phone in September 2019. The company claimed to have sold one million units since launch by December 2019, but Samsung later denied having sold 1 million units, and admitted having reported sales expectations as actual sales. The second generation model, Galaxy Z Fold 2, was announced in August 2020.

"It's okay to be white" (IOTBW) is an alt-right slogan which originated as part of an organized trolling campaign on the website 4chan's discussion board /pol/ in 2017. A /pol/ user described it as a proof of concept that an otherwise innocuous message could be used maliciously to spark media backlash. Posters and stickers stating "It's okay to be white" were placed in streets in the United States as well as on campuses in the United States, Canada, Australia, and the United Kingdom.

The slogan has been supported by white supremacists and neo-Nazis.