AmigaDOS is the disk operating system of the AmigaOS, which includes file systems, file and directory manipulation, the command-line interface, and file redirection.

In AmigaOS 1.x, AmigaDOS was based on a TRIPOS port by MetaComCo, written in BCPL. BCPL does not use native pointers, so the more advanced functionality of the operating system was difficult to use and error-prone. The third-party AmigaDOS Resource Project (ARP, formerly the AmigaDOS Replacement Project), a project begun by Amiga developer Charlie Heath, replaced many of the BCPL utilities with smaller, more sophisticated equivalents written in C and assembler, and provided a wrapper library, arp.library. This eliminated the interfacing problems in applications by automatically performing conversions from native pointers (such as those used by C or assembler) to BCPL equivalents and vice versa for all AmigaDOS functions.

From AmigaOS 2.x onwards, AmigaDOS was rewritten in C, retaining 1.x compatibility where possible. Starting with AmigaOS 4, AmigaDOS abandoned its legacy with BCPL. Starting from AmigaOS 4.1, AmigaDOS has been extended with 64-bit file-access support.

Maria Bethânia Vianna Telles Veloso (born 18 June 1946 in Santo Amaro da Purificação, Bahia Brazil), better known as Maria Bethânia (Portuguese pronunciation: [maˈɾiɐ beˈtɐ̃niɐ]), is a singer and sister of Caetano Veloso. She started her career in Rio de Janeiro in 1964 with the show "Opinião" ("Opinion"). Due to its popularity, and the popularity of her 1965 single "Carcará", the singer became a star in Brazil, with performances all over the country. She has released over 30 albums to date.

In her childhood, Bethânia had aspirations to become an actress. However, her mother was a musician, so music was prevalent in the Veloso household. Though Bethânia was born in Santo Amaro da Purifição, her family moved to Salvador, Bahia when she was 13 years old. The move allowed her to experience the bohemian, intellectual circles of the city as well as to visit theaters. When she was 16, her brother Caetano Veloso invited her to sing in a film for which he was producing the soundtrack, but she refused. However, the film's director, Álvaro Guimarães, liked her voice and invited the young musician to perform in a 1963 performance of a Nélson Rodrigues musical. She began performing again with her brother, as well as Gilberto Gil, Gal Costa, and Tom Zé, at the opening of the Vila Velha Theater in the next year. During one of these performances, the bossa nova musician Nara Leão offered her an opportunity to take her place in a series of performances titled "Opinião". She released her first single, a protest song named "Carcará", in 1965, the same year as her brother released his first recording.

"Jack the Ripper" is the best-known name given to an unidentified serial killer who was active in the largely impoverished areas in and around the Whitechapel district of London in 1888. The name originated in a letter, written by someone claiming to be the murderer, that was disseminated in the media. The letter is widely believed to have been a hoax, and may have been written by a journalist in a deliberate attempt to heighten interest in the story. Other nicknames used for the killer at the time were "The Whitechapel Murderer" and "Leather Apron".

Attacks ascribed to the Ripper typically involved female prostitutes from the slums whose throats were cut prior to abdominal mutilations. The removal of internal organs from at least three of the victims led to proposals that their killer possessed anatomical or surgical knowledge. Rumours that the murders were connected intensified in September and October 1888, and letters from a writer or writers purporting to be the murderer were received by media outlets and Scotland Yard. The "From Hell" letter, received by George Lusk of the Whitechapel Vigilance Committee, included half of a preserved human kidney, supposedly from one of the victims. Mainly because of the extraordinarily brutal character of the murders, and because of media treatment of the events, the public came increasingly to believe in a single serial killer known as "Jack the Ripper".