All articles starting with O

Open Whisper Systems

Open Whisper Systems was the software project led by Moxie Marlinspike that developed the encrypted apps TextSecure and RedPhone, merged them into Signal, and created the Signal protocol.

Open Windows is a 2014 screenlife techno-thriller, Nacho Vigalondo's third feature and first in English, starring Elijah Wood, Sasha Grey, and Neil Maskell; the entire film plays on a laptop screen in real time, grossed $550,108 worldwide, and scored 40% on Rotten Tomatoes.

Open world

Open world (also sandbox) game design: players freely roam a large virtual world and choose when to pursue objectives. Traces to Colossal Cave Adventure (1976) and Elite (1984); GTA III (2001) defined the 3D form; market projected at $67.26B by 2035.

Open wound of forearm

Open wound of forearm (ICD-11 NC31): traumatic skin break of the forearm, coded as laceration, puncture, open bite, or multiple wounds; managed by hemostasis, irrigation, closure, and referral for arterial, nerve, or tendon injury.

Open wound of head

Open wound of head (ICD-11 NA01; ICD-10 S01) is an injury classification covering lacerations, puncture wounds, open bites, and multiple open wounds of the head, most commonly scalp lacerations with heavy bleeding from the scalp's rich blood supply.

Open wound of neck

Open wound of neck: a traumatic breach of neck skin and soft tissue, ICD-10 category S11 and ICD-11 code NA21. Covers lacerations, punctures, and open bites; mortality 2-5% for penetrating neck trauma, about 70% with major vessel rupture.

Open wound of toe

Open wound of toe: a cut or break in toe skin, classified in ICD-11 as block ND12.6 (lacerations, punctures, open bites, with or without foreign body) and ICD-10-CM as S91.1; foot location and puncture mechanism raise infection risk.

Open X-Embodiment

Open X-Embodiment (OXE) is a pooled dataset of more than one million real robot trajectories spanning 22 robot embodiments, assembled by robotics labs in October 2023.

Open Your Eyes (1997 film)

Open Your Eyes (Abre los ojos) is a 1997 Spanish psychological sci-fi thriller by Alejandro Amenábar, starring Eduardo Noriega and Penélope Cruz, about a disfigured man in a programmed cryonic dream; remade as Vanilla Sky (2001).

Open Your Heart or Die Trying

Open Your Heart or Die Trying is Arcade Fire's 2026 ambient companion album to Pink Elephant, released via Columbia for Record Store Day and digitally May 1, 2026; eight instrumental tracks, 36 minutes, reworking Pink Elephant as a score to an unmade film.

Open-air display of Great Patriotic War military equipment

Пляцоўка баявой тэхнікі часоў Вялікай Айчыннай вайны: open-air displays of WWII-era Soviet combat equipment at memorials such as Loyev's Battle of the Dnieper museum, Stalin Line, and the Minsk war museum, showing T-34, IS tanks, Katyushas, and artillery.

Open-circuit test

The open-circuit test, or no-load test, is an electrical test on a transformer in which one winding is energized at rated voltage to measure core loss and shunt parameters.

Open-circuit voltage deficit

The open-circuit voltage deficit is the difference between a solar cell's theoretical Shockley–Queisser voltage limit and its measured open-circuit voltage, a figure of merit for photovoltaic quality.

Open-core model

The open-core model is a business model in which a feature-limited open-source core is released free while extra features are sold as proprietary add-ons or plugins.

Open-die forging

Open-die forging, also called smith or flat-die forging, is a hot forming process that shapes heated metal between flat dies that do not enclose the workpiece.

Oct 10, 2026

Open-economy macroeconomics

Open-economy macroeconomics is the branch of macroeconomics that studies how trade in goods, services, and assets changes output, interest rates, exchange rates, and policy, including the trilemma limiting fixed rates, capital mobility, and monetary independence.

Open-face shield tunnelling

Open-face shield tunnelling is a method in which a rigid steel shield is pushed through soft ground with the tunnel face left unsupported, workers protected by boards, shelves, and hoods.

Open-graded friction course

An open-graded friction course (OGFC) is a thin, porous asphalt surface layer that lets water drain through it, improving wet-weather friction, reducing hydroplaning risk, and cutting tire noise.

Sep 29, 2026

Open-loop controller

An open-loop controller applies a predetermined input to a system without measuring the output, so it cannot correct errors from disturbances; examples include toasters and traffic lights.

Open-loop transfer function

The open-loop transfer function of a feedback control system is the product of all loop transfer functions with the feedback opened, L(s) = C(s)P(s), the basis of Bode, Nyquist, and gain and phase margin analysis.

Open-mid back rounded vowel

Open-mid back rounded vowel, also called low-mid back rounded vowel or "open-o", is the IPA vowel ⟨ɔ⟩ (U+0254): back, open-mid height, rounded lips; allophone of /ɒ/ in RP and Australian English, vowel of GA caught.

Open-net pen salmon farming controversy

The open-net pen salmon farming controversy concerns salmon raised in coastal sea cages, their effects on wild salmon, and Canada's 2029 ban in British Columbia.

Open-pit mining

Open-pit mining, also called opencast or open-cut mining, is a surface method that extracts near-surface ore from benches in a deepening pit; Utah's Bingham Canyon is a notable example.

Open-RMF

Open-RMF (Open Robotics Middleware Framework) is a free, open source middleware system that lets multiple robot fleets share infrastructure like doors, elevators, and building management systems, first developed for healthcare.

Open-Sora

Open-Sora is an open-source text-to-video and image-to-video generation model by HPC-AI Tech, reproducing the techniques in OpenAI's Sora report; version 2.0, an 11B-parameter model, was released in 2025.

Open-source hardware

Open-source hardware, also known as free or libre hardware, is physical hardware whose design is publicly available so anyone can study, modify, make, and sell it.

Open-source intelligence

Open-source intelligence (OSINT): intelligence produced by collecting, verifying, and analyzing publicly or commercially available information. Roots in WWII broadcast monitoring (BBC 1939, FBMS 1941); now spans journalism, human rights, and cybersecurity.