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Riding boots
Riding boots are footwear for motorcycles and horses, characterized by a shaft that covers the ankle and a heel designed for grip and control, protecting the user during rides.
Riedel (glassware)
Riedel is an Austrian crystal glassware manufacturer, founded in Bohemia in 1756 and still family-run in its eleventh generation from Kufstein, Tyrol, known for popularizing grape varietal specific glassware, glasses shaped for each wine style.
Rieter
Rieter is a Swiss technology group headquartered in Winterthur that makes machinery and systems for spinning yarn, founded in 1795 and known as the leading supplier of short-staple spinning systems.
Rietveld Schröderhuis (Rietveld Schröder House)
The Rietveld Schröder House is a 1924 De Stijl house in Utrecht, Netherlands, designed by Gerrit Rietveld and added to the UNESCO World Heritage List in 2000.
Rievaulx Abbey
Rievaulx Abbey is the ruin of a medieval Cistercian monastery in the River Rye valley near Helmsley, North Yorkshire, founded in 1132 and dissolved by Henry VIII in 1538.
RIFE
RIFE (Real-Time Intermediate Flow Estimation) is a neural network algorithm for video frame interpolation that estimates intermediate optical flow directly, 4 to 27 times faster than SuperSlomo and DAIN.
Riffusion
Riffusion is an open-source AI music-generation model family created by Seth Forsgren and Hayk Martiros in December 2022, fine-tuning Stable Diffusion to generate spectrogram images converted into audio.
Rifle
A rifle is a shoulder-fired firearm whose barrel is cut with spiral grooves that spin the projectile, distinguishing it from the smoothbore shotgun and giving long-range accuracy.
Rifle grenade
A rifle grenade is a grenade designed to be launched from a rifle's muzzle, projecting it up to 218 yards and filling the gap between hand grenades and mortars.
Rifled muzzle loader
A rifled muzzle loader (RML) is an artillery piece with a rifled bore that is loaded through the muzzle, dominating heavy guns from the 1860s to the 1880s.
Rifling
Rifling, or a rifled barrel, is a set of helical grooves machined into a firearm barrel that spins the projectile for stability, used since the 1490s and central to forensic bullet identification.
Riga International Airport
Riga International Airport (RIX) is Latvia's main airport and the largest Baltic aviation hub, about 10 km from central Riga. It handled 7.1 million passengers and 20,100 tonnes of cargo in 2025 and is expanding its terminal by 2030.
Rigaku
Rigaku is a Japanese manufacturer of X-ray analytical and measurement instruments, founded in Tokyo in 1951 and headquartered in Akishima, known for X-ray diffraction and semiconductor metrology.
Riggs Bank
Riggs Bank (Riggs National Bank of Washington, D.C.), 1840-2005 Washington bank known as the Bank of Presidents; served 23 presidents and 95 percent of DC embassies; headquarters now the Riggs Washington DC hotel.
Right to repair
The right to repair is a consumer movement and policy principle holding that owners and independent shops can fix products using the parts, tools, and documentation manufacturers provide.
Right turn on red
Right turn on red (RTOR) is a traffic rule, used in the United States and similar regions, allowing a right turn at a red light after stopping unless prohibited.
Right-of-way (transmission)
A right-of-way in electric power transmission is the strip of land under a transmission line over which the utility holds rights to build, operate, and maintain the line.
RightHand Robotics
RightHand Robotics is an American warehouse robotics company in Charlestown, Massachusetts, founded in 2015, whose RightPick system grasps individual items from bins for e-commerce fulfillment.
Righting moment
The righting moment, also called the moment of statical stability, is the torque that returns a heeled ship upright, equal to its displacement multiplied by the righting lever GZ.
Rigid airship
A rigid airship is a lighter-than-air aircraft with a stiff internal airframe holding its gas cells, pioneered by Count Zeppelin's LZ 1 in 1900 and ended by the 1937 Hindenburg fire.
Rigid coaxial transmission line
Rigid coaxial transmission line, or rigid line, is a high-power radio-frequency feeder of straight copper conductors with air dielectric, assembled in short flanged sections used chiefly in broadcast transmitter plants.
Rigid image registration
Rigid image registration, also called rigid registration, aligns two views of an object using only translation and rotation, commonly applied to medical scans of the same patient.
Rigid inflatable boat
A rigid inflatable boat (RIB), or rigid-hulled inflatable boat, combines a solid hull with an inflatable collar, giving speed plus buoyancy for rescue, military, and leisure use.
Rihand converter station
The Rihand converter station is the sending-end terminal of the Rihand–Dadri HVDC link, a 1,500 MW system carrying power from Uttar Pradesh toward Delhi since 1990.
Rihand power station
Rihand power station, also known as Rihand Super Thermal Power Station, is a 3,000 MW NTPC coal-fired power station at Rihandnagar in Sonebhadra district, Uttar Pradesh, India.
RIIO-T3
RIIO-T3 is the price control set by the British regulator Ofgem for Great Britain's electricity and gas transmission networks, running from April 2026 to March 2031 as the transmission part of the RIIO-3 round.
Rijksbouwbesluit
The Rijksbouwbesluit is the Dutch national building decree under the Housing Act, which replaced varying municipal bylaws in 1992 with uniform performance requirements and was succeeded by the Bbl in 2024.
Rijkswaterstaat
Rijkswaterstaat is the executive agency of the Dutch Ministry of Infrastructure and Water Management, managing the main road network, waterways, and flood defenses since 1798.
Rik Huiskes
Rik Huiskes (Hendrik Willem Jan Huiskes, 1944–2010) was a Dutch biomechanics researcher who modeled bone remodeling around joint prostheses and edited the Journal of Biomechanics.
Rik W. De Doncker
Rik W. De Doncker is a Belgian electrical engineer and professor at RWTH Aachen University, best known for inventing the dual-active-bridge DC-DC converter in 1988.