All articles A–Z

Altimeter Venture Partners

Altimeter Venture Partners is the venture capital fund series managed from Boston, Massachusetts, under which Brad Gerstner's Altimeter Capital raises venture vehicles, including Fund VII, a Delaware limited partnership formed in 2023.

Altimir

Altimir (Алтимир) is a village in Byala Slatina municipality, Vratsa Province, Bulgaria, on the Skut river, with a Neolithic settlement at Bresta, a Bronze Age barrow necropolis, and a Roman fort; not the Catalan surname or the French Altimir case.

Altin Dilyar tepe

Altin Dilyar tepe, also spelled Altïn Dilyār, is an unexcavated Achaemenid-period (ca. 6th–4th century BCE) circular walled town of about 15 hectares with a 28-meter citadel, in Dawlatabad District, Balkh Province, Afghanistan, north of Balkh.

Altina Schinasi

Altina Schinasi (1907–1999), American artist and designer, invented the Harlequin "cat-eye" eyeglass frame in the late 1930s, won the 1939 Lord & Taylor American Design Award, and later directed the Oscar-nominated documentary George Grosz' Interregnum.

Altinum (Romania)

Altinum (Altina) was a Roman castrum and civilian settlement at Oltina, Dobrogea, Romania, on the Danube limes between Durostorum and Sacidava; garrisoned by ala I Gallorum Flaviana, a fleet base of Moesia Secunda, rebuilt under Justinian I.

Altiplano

Altiplano: high internally drained plateau of the central Andes (Bolivia, Peru), northern part of the Altiplano-Puna plateau, 1,800 km long, second highest plateau on Earth, formed by crustal shortening at a subduction margin, not collision.

Altira Technology

Altira Technology is a Denver, Colorado-based venture capital firm investing in growth-stage energy technology, emphasizing oil and gas operations, digital solutions, automation, and emissions reduction.

Altishahr

Altishahr ("Six Cities") is the historical Turkic name for the Tarim Basin oasis region of southern Xinjiang, also called Yettishahr, Kashgaria, or Nanjiang; conquered by the Qing in 1759-60.

Altitude

Altitude is the vertical distance from mean sea level to the point being measured, a definition the World Meteorological Organization gives legal status to in its Technical Regulations.

Altitude (triangle)

An altitude of a triangle is a line segment from a vertex perpendicular to the opposite side; the three altitudes meet at a point called the orthocenter.

Altitude Angel

Altitude Angel was a British aviation technology company based in Reading, founded in 2014 by Richard Parker, that built GuardianUTM software for integrating drones into shared airspace.

Altitude Life Science Ventures

Altitude Life Science Ventures is a privately held venture capital firm in Kirkland, Washington, founded in 2004 by David Maki to invest in early-stage life science companies.

Altitude sickness

Altitude sickness (altitude illness): AMS, HACE, and HAPE caused by hypobaric hypoxia above about 2,450 m. Prevented by gradual ascent and acetazolamide; treated by descent.

Altitude test

An altitude test is an environmental laboratory test that exposes a product to low air pressure simulating high altitude or aircraft conditions, most commonly under MIL-STD-810 Method 500.6.

Altitude test cell

An altitude test cell is an enclosed ground facility that runs an aircraft or rocket engine under controlled pressure, temperature, and airflow simulating flight at altitude.

Altium

Altium is a San Diego, California, electronic design automation company known for Altium Designer, a printed circuit board design application, and Altium 365, a cloud collaboration platform.

Altium Designer

Altium Designer is a commercial electronic design automation application for designing printed circuit boards, begun as Protel PCB in 1985 and covering schematic capture, layout, and simulation.

Altius (loitering munition)

Altius is a family of tube-launched expendable drones developed by Area-I and now produced by Anduril Industries, flown for reconnaissance or as a loitering munition.

AltiVec

AltiVec, which Apple marketed as the Velocity Engine and IBM calls VMX, is a SIMD vector extension to PowerPC, adding 32 128-bit vector registers, first shipped in 1999.

Sep 19, 2026

Altın Gün

Altın Gün (Altin Gun) is a Grammy-nominated Turkish psychedelic rock and funk band formed in Amsterdam in 2016, rearranging Turkish folk songs in the 1970s Anatolian psych-funk style.

Altındağ

Altındağ (Ankara district), Turkey's capital's historic core with Ankara Castle, known as Eski Ankara. 418,072 residents (2025), 26 neighborhoods, 157.47 km², second densest Ankara district, major urban transformation area.

Altman Z-score

The Altman Z-score is a bankruptcy-prediction model combining five financial ratios into a single weighted score classifying firms as safe, gray, or distressed, published in 1968.

Oct 10, 2026

Altmann

Altmann, bishop of Passau from 1065 and venerated as a saint, backed Pope Gregory VII in the Investiture Controversy, was expelled by Henry IV, and founded Göttweig Abbey.

Altmark

Altmark: historic cultural landscape in northern Saxony-Anhalt, Germany, west of the Elbe; "old mark", cradle of Brandenburg-Prussia; Hanseatic towns Stendal and Salzwedel; agricultural region of about 5,000 km².

Altmark incident

The Altmark incident: British destroyer HMS Cossack boarded the German supply ship Altmark in Norway's Jøssingfjord on 16 February 1940, freeing 299 British prisoners, violating Norwegian neutrality and accelerating German planning for the invasion of Norway.