Darwin is an open-source Unix-like operating system first released by Apple Inc. in 2000. It is composed of code developed by Apple, as well as code derived from NeXTSTEP, BSD, other free software projects. Darwin forms the core set of components upon which macOS, iOS, watchOS, tvOS, iPadOS are based, it is POSIX-compatible, but has never, by itself, been certified as compatible with any version of POSIX. Starting with Leopard, macOS has been certified as compatible with the Single UNIX Specification version 3; the heritage of Darwin began with NeXT's NeXTSTEP operating system, first released in 1989. After Apple bought NeXT in 1997, it announced it would base its next operating system on OPENSTEP; this was developed into Rhapsody in 1997, Mac OS X Server 1.0 in 1999, Mac OS X Public Beta in 2000, Mac OS X 10.0 in 2001. In 1999 Apple announced it would release the Mach 2.5 microkernel, BSD Unix 4.4 OS, the Apache Web server components of Mac OS X Server. At the time interim CEO Steve Jobs alluded to British naturalist Charles Darwin by announcing "because it's about evolution".

In 2000, the core operating system components of Mac OS X were released as open-source software under the Apple Public Source License as Darwin. Up to Darwin 8.0.1, Apple released a binary installer after each major Mac OS X release that allowed one to install Darwin on PowerPC and Intel x86 systems as a standalone operating system. Minor updates were released as packages. Darwin is now only available as source code, except for the ARM variant, which has not been released in any form separately from iOS, watchOS, or tvOS. A hobbyist developer winocm took the official Darwin source code and ported it to ARM; the kernel of Darwin is XNU, a hybrid kernel which uses OSFMK 7.3 from the OSF, various elements of FreeBSD, an object-oriented device driver API called I/O Kit. The hybrid kernel design provides the flexibility of a microkernel and the performance of a monolithic kernel. Darwin includes support for the 64-bit x86-64 variant of the Intel x86 processors used in Macs and the 64-bit ARM processors used in the iPhone 5S, the 6th generation iPod Touch, the iPad Air, the fourth generation Apple TV, original HomePod, models, as well as the 32-bit ARM processors used in the iPhone 5C and older, earlier generations of the iPod Touch, the iPad up to the fourth generation, the second and third generation Apple TV.

An open-source port of the XNU kernel exists that supports Darwin on Intel and AMD x86 platforms not supported by Apple, though it does not appear to have been updated since 2009. An open-source port of the XNU kernel exists for ARM platforms. Older versions supported some or all of 32-bit PowerPC, 64-bit PowerPC, 32-bit x86, it supports the POSIX API by way of its BSD lineage and a large number of programs written for various other UNIX-like systems can be compiled on Darwin with no changes to the source code. Darwin does not include many of the defining elements of macOS, such as the Carbon and Cocoa APIs or the Quartz Compositor and Aqua user interface, thus cannot run Mac applications, it does, support a number of lesser known features of macOS, such as mDNSResponder, the multicast DNS responder and a core component of the Bonjour networking technology, launchd, an advanced service management framework. In July 2003, Apple released Darwin under version 2.0 of the Apple Public Source License, which the Free Software Foundation classifies as a free software license incompatible with the GNU General Public License.

Previous versions were released under an earlier version of the APSL license, which did not meet the FSF definition of free software, although it did meet the requirements of the Open Source Definition. The following is a table of major Darwin releases with their dates of release and their corresponding macOS releases. Note that the corresponding macOS release may have been released on a different date; the jump in version numbers from Darwin 1.4.1 to 5.1 with the release of Mac OS X v10.1.1 was designed to tie Darwin to the Mac OS X version and build numbering system, which in turn is inherited from NeXTSTEP. In the build numbering system of macOS, every version has a unique beginning build number, which identifies what whole version of macOS it is part of. Mac OS X v10.0 had build numbers starting with 4, 10.1 had build numbers starting with 5, so forth. The command uname -r in Terminal will show the Darwin version number, the command uname -v will show the XNU build version string, which includes the Darwin version number.

Due to the free software nature of Darwin, there have been projects that aim to modify or enhance the operating system. OpenDarwin was a community-led operating system based on the Darwin system, it was founded in April 2002 by Internet Systems Consortium. Its goal was to increase collaboration between the free software community. Apple benefited from the project because improvements to OpenDarwin would be incorporated into Darwin releases. On July 25, 2006, the OpenDarwin team announced that the project was shutting down, as they felt OpenDarwin had "become a mere hosting facili

Campbell's law is an adage developed by Donald T. Campbell, a psychologist and social scientist who wrote about research methodology, which states: "The more any quantitative social indicator is used for social decision-making, the more subject it will be to corruption pressures and the more apt it will be to distort and corrupt the social processes it is intended to monitor." Campbell's law can be seen as an example of the cobra effect, the sometimes unintended negative effect of public policy and other government interventions in economics and healthcare. In 1976, Campbell wrote: "Achievement tests may well be valuable indicators of general school achievement under conditions of normal teaching aimed at general competence, but when test scores become the goal of the teaching process, they both lose their value as indicators of educational status and distort the educational process in undesirable ways."The social science principle of Campbell's law is used to point out the negative consequences of high-stakes testing in U.

S. classrooms. This may take the form of teaching to outright cheating. "The High-Stakes Education Rule" is identified and analyzed in the book "Measuring Up: What Educational Testing Really Tells Us". Campbell’s Law helps people discern that the Obama administration program of Race to the Top and Bush administration program, the No Child Left Behind Act can impair, not improve, educational outcome. There are related ideas known by different names, such as Goodhart's law and the Lucas critique. Another concept related to Campbell's law emerged in 2006 when UK researchers Rebecca Boden and Debbie Epstein published an analysis of evidence-based policy, a practice espoused by Prime Minister Tony Blair. In the paper and Epstein described how a government that tries to base its policy on evidence can end up producing corrupted data because it "seeks to capture and control the knowledge producing processes to the point where this type of'research' might best be described as'policy-based evidence'."When someone distorts decisions in order to improve the performance measure, they surrogate, coming to believe that the measure is a better measure of true performance than it is.

Campbell's Law imparts a complicated message. It is important to measure progress making use of qualitative indicators. However, utilizing quantitative data for evaluation can manipulate these indicators. Concrete measures must be adopted to reduce manipulation of information. In his article, “Assessing the Impact of Planned Social Change”, Campbell emphasized that “the more quantitative social indicator used for social decision-making is subjected to corruption pressure and liable to distort and damage social processes it meant to monitor.” Perverse incentive Reflexivity Proxy Goodhart's law – "When a measure becomes a target, it ceases to be a good measure." Observer effect

St Dogmael's Abbey is an abbey in St Dogmaels in Pembrokeshire, Wales, on the banks of the River Teifi and close to Cardigan and Poppit Sands. It is named after Dogmael, a 6th-century saint said to have been the son of Ithel ap Ceredig ap Cunedda Wledig, reputedly the cousin of Saint David; the abbey was built on or close to the site of the pre-Norman conquest clas church of Llandudoch. It was founded twelve monks of the Tironensian Order; the founders were his wife, Maud Peverel. In 1120 Abbot William of Tiron consented to fitz Martin's request. Abbot Fulchard was installed by Bishop Bernard of St David's, it remained a daughter house of Tiron until its dissolution. However, in 1138, the village and abbey of St Dogmaels were sacked by Gruffudd ap Cynan's sons, Owain Gwynedd and Cadwaladr, acting with princes Anaraud and Cadell. In 1188, Gerald of Wales stayed at the abbey with Baldwin, Archbishop of Canterbury, whilst they gathered support for the Third Crusade on their preaching tour of Wales.

The earliest surviving remains date from the first half of the twelfth century. It seems that sufficient of the church was built to satisfy the immediate requirements of the monastery, but that the western part for the use of the laity, was not finished; the nave was completed although without the intended aisles. Unusually the church lacks a west doorway because of the slope of the ground becomes steeper; the square-ended sanctuary was built over a vaulted crypt a repository for relics of St Dogmael. About the middle of the thirteenth century, the cloister was enlarged northwards; the domestic quarters were extensively rebuilt at the end of the thirteenth or beginning of the fourteenth century. A new infirmary was built, followed by a chapter house In the fourteenth or fifteenth century, much of the west range was altered to provide improved accommodation for the abbot. A new wing was added for the abbot's guests; the last alteration to the church was the rebuilding of the north transept, with its elaborate fan vaulted roof.

This happened in the early sixteenth century, not long before the suppression of the monastery. The lavish design indicates it may have been an individually distinct chapel built as a memorial to the founder's family, the lords of Cemais; the abbey was dissolved in 1536, along with hundreds of other houses whose annual income was less than £200. By this time, there were the abbot; the majority of the abbey's possessions were leased to John Bradshaw of Presteigne in Radnorshire. He built a mansion within the abbey precinct. Substantial parts of the church survive, including the western end wall, the north wall, northern transept; the crypt, beneath the former eastern two bays of the presbytery is preserved to the springing of the vault. Fifteenth century floor tiles remain in large areas of the nave; the abbey is Grade I listed. The abbey was known for its library. One manuscript, a 13th-century copy of Eusebius's Historia Ecclesiastica, survives and is housed in St John's College, Cambridge. Www.geograph.co.uk: photos of St Dogmaels Abbey and surrounding area:The heritage and history of the abbey and the village

Town of Halifax Court House Historic District is a national historic district located at Halifax, Halifax County, Virginia. The district includes 172 contributing buildings, 1 contributing site, 13 contributing structures, 1 contributing object in the Town of Halifax. Resources include government, residential, religious and industrial buildings that date from the early-19th Century to the mid-20th century. Notable buildings include the Rice House, Edmunds/Lewis Office, People's Bank, Beth Car Baptist Church, Christ Episcopal Church, Saint Luke's Christian Methodist Episcopal Church, Dr. Carter House, County Office Building, Town of Halifax Swimming Pool, Municipal Building/ Fire Station, Halifax Roller Mills, Halifax Planing Mill, Halifax Department Store, Randolph Theater. Located in the district is the separately listed Halifax County Courthouse, it was listed on the National Register of Historic Places in 2011

Nick Theslof is an American soccer manager and coach, midfield coach and international scout to Jürgen Klinsmann at FC Bayern Munich. He is an assistant coach for Toronto FC in Major League Soccer, he was one of the first and youngest American soccer players to have played in continental Europe, joining PSV Eindhoven's youth side in 1991 and playing there for two years. Coming from a sporting family, his grandparents were leading Swedish figure skater Vivi-Anne Hultén and Finnish figure skater Gene Theslof. Having grown up in a family of renowned skaters, with both his grandparents and parents being skaters, Theslof was exposed to sports being a viable career option from a early age. While his younger brother Tyler chose to become an ice hockey goaltender, Nick was interested in soccer and began playing for the youth indoor soccer club, the Cleveland Crunch. In 1991, his coach at the club, former English striker Ron Wigg, advised PSV Eindhoven head of youth development Huub Stevens to have a look at Theslof, during a match for which PSV's reserve team had come to Cleveland.

Stevens, impressed with Theslof's potential, offered him a youth contract at PSV, which Theslof accepted and moved from his home in Columbus to Eindhoven, the Netherlands. He subsequently played for PSV for the next two years, before his career abruptly ended due to an Achilles injury, he moved back to the United States and attended UCLA, where he played for their soccer team, where his performances were lauded. On February 1, 1998, the Columbus Crew selected Theslof in the 1998 MLS College Draft, but he was released during the 1998 season without playing a first team game, he moved to the Orange County Waves for the 2000 USL A-League season. In 2005 and 2006, Thesloff inserted himself into several Blue Star games. Theslof began his coaching career as Dr. Jay Martin's assistant at Ohio Wesleyan University between 1998 and 2000, winning the NCAA Division III national title in 1998. Following his stay at Ohio Wesleyan, Theslof became head coach of the Orange County Blue Star, a team of the American Premier Development League and spent time with Juergen Klinsmann who enjoyed Amateur Soccer in Southern California.

During that time he coached future American national team players Sacha Kljestan and Sal Zizzo. In 2004, Theslof coached his old club PSV's youth squad in the Netherlands. After Klinsmann became manager of the German national team, he appointed Theslof as coach and scout in 2006 during the 2006 FIFA World Cup, where he wrote detailed match summaries and reports for Klinsmann. In February 2008, after he was appointed manager of FC Bayern Munich, Klinsmann appointed Theslof as a second assistant coach and scout. On April 27, 2009 Klinsmann and his two assistant coaches were released early though they had won five of the previous seven league games and were only three points behind league leader VfL Wolfsburg

Martín Antonio Alvarado Nieves is a Mexican luchador, or professional wrestler best known under the ring name Súper Brazo and is part of an extensive Alvarado wrestling family, founded by his father Shadito Cruz and includes Alvarado's five brothers as well as a large number of third generation wrestlers. Most of the wrestlers in the Alvarado family is using or has used a ring name with the word "Brazo" in it at some point in their career. Martín Alvarado has worked for a number of Mexican professional wrestling promotion, but is working on the Mexican Independent circuit and not permanently for one specific promotion. Martín Alvarado was trained by his father Shadito Cruz before making his professional wrestling career on July 7, 1983, he wrestled as an enmascarado or masked character called "Frayle Pop", but lost that mask as a result of a Luchas de Apuestas, or "bet match" loss to Robin Hood and revealed that he was part of the Alvarado family. At the time it was not revealed that Robin Hood was a brother of Martín Alvarado, José Aarón Alvarado Nieves.

A few years he took the family ring name and became known as Súper Brazo, including the signature "Brazo" mask with the logo of a man flexing his biceps on the front of it. While his three oldest brothers had worked as "Los Brazos" and other Brazos had at times replaced one of them, Super Brazo, Brazo Cibernético and Brazo de Platino work as Los Nuevo Brazos for the Universal Wrestling Association starting in 1992. On Súper Brazo worked for Consejo Mundial de Lucha Libre, the world's oldest and one of Mexico's largest wrestling promotions. In CMLL he became involved in a storyline with Mr. Niebla that escalated to the point that both wrestlers put their mask on the line in a Luchas de Apuestas match; the match was won by Mr. Niebla, forcing Súper Brazo to unmask. In the years following his mask loss Súper Brazo became a regular on the Mexican Independent Circuit around Mexico City, oftentimes teaming with Brazo de Platino and Brazo Cibernético until his death in 1999. Over the years Súper Brazo became more of a "Special attraction" wrestler, brought in by a promoter for a few events but not working long term for any promotion.

Súper Brazo, as well as most of the other second generation Alvarado brothers lost their hair in Luchas de Apuestas matches, losing to wrestlers such as Apolo Dantés, Máscara Año 2000, Villano III, Pierroth, Jr. and others. Súper Brazo has won the hair of his brother Brazo de Platino on at least two occasions, both times as a result of the brothers losing a Relevos Suicidas where they were forced to fight each other as a result. On February 2, 2013 Súper Brazo and Brazo de Platino took part in another chapter in the decade long feud between the Alvarado brothers and Los Villanos as the two lost a Luchas de Apuestas to Villano III and Villano IV and was once again shaved bald. On February 17, 2013 Súper Brazo and the rest of the Alvarado family held a special show, Homenaje a Shadito Cruz where he teamed up with his brother Brazo de Platino and competed in the La Copa Shadito Cruz tournament, defeating El Hijo de Fishman and El Hijo de Canek before losing to their nephews Máximo and La Máscara in the semi-finals of the tournament.

The Alvarado wrestling family spans three generations starting with Shadito Cruz followed by his 6 sons and a third generation of wrestlers that started working in the late 1990s. Several wrestlers has used the ring name "Súper Brazo" and claimed to be related to Martín Alvarado, although in some cases the family connection is fictional. Alvarado himself confirmed that the Súper Brazo, Jr. that made his debut around 2000, is indeed a biological son, but a "Super Brazo II" was not, but given the character by Alvarado to carry on the name. The wrestler known as Brazo Celestial started out in 2009 wrestling as "Super Brazo, Jr." but may not be the son of Martin Alvarado. There are cases where the sons of José Alvarado Nieves have used the ring names of their uncles as there was someone working as "Brazo de Plata, Jr." It remains unconfirmed how Brazo Celestial is related to the Alvarado family, only that he indeed is a member of the family.† = deceased