Question: What company published the video game whose main protagonist is Altaïr Ibn-La'Ahad?

Context paragraphs:
Lara Croft: Lara Croft is a fictional character and the main protagonist of the Square Enix (previously Eidos Interactive) video game franchise "Tomb Raider".  She is presented as a highly intelligent, athletic, and beautiful English archaeologist-adventurer who ventures into ancient, hazardous tombs and ruins around the world.  Created by a team at UK developer Core Design that included Toby Gard, the character first appeared in the 1996 video game "Tomb Raider".  She has also appeared in video game sequels, printed adaptations, a series of animated short films, feature films (portrayed by Angelina Jolie, later by Alicia Vikander), and merchandise related to the series.  Official promotion of the character includes a brand of apparel and accessories, action figures, and model portrayals.  Croft has also been licensed for third-party promotion, including television and print advertisements, music-related appearances, and as a spokesmodel.  As of June 2016, Lara Croft has been featured on over 1,100 magazine covers surpassing any supermodel.

Assassin's Creed (video game): Assassin's Creed is an action-adventure stealth video game developed by Ubisoft Montreal and published by Ubisoft.  It is the first installment in the "Assassin's Creed" series.  The game was released for PlayStation 3 and Xbox 360 in November 2007, and was made available on Microsoft Windows in April 2008.

Assassin's Creed: Altaïr's Chronicles: Assassin's Creed: Altaïr's Chronicles is a video game released for the Nintendo DS, Android, iOS, webOS, Symbian, Java ME and Windows Phone.  It is a prequel to the 2007 video game "Assassin's Creed", developed by Gameloft and published by Ubisoft.  It was released in the United States on February 5, 2008.  It features two new cities, Tyre and Aleppo; and the three original cities, Jerusalem, Acre, and Damascus; but does not include Masyaf.  Unlike the original "Assassin's Creed", the game is not told through the perspective of Desmond Miles, but rather the perspective of Altaïr Ibn-La'Ahad, although the menu screens do take place in the Animus.

Altaïr Ibn-La'Ahad: Altaïr Ibn-La'Ahad (Arabic: الطائر ابن لا أحد‎ ‎ , meaning "The Flying Eagle, Son of None") is a fictional character in the "Assassin's Creed" series.  He is one of the main members of the Assassin's Brotherhood.  He was trained by Al-Mualim, his guardian since childhood.  He was trained in the Masyaf Castle in Syria.  He serves as the main protagonist of "Assassin's Creed", "" and "".  Altaïr also shares the role as protagonist in "" with Ezio Auditore da Firenze and is playable once in "Assassin's Creed II".  He was generally well received by critics and gamers alike, although Philip Shahbaz's voice-over performance was widely derided.

Electro Brain: Electro Brain was a United States video game company.  They brought over "" for the Nintendo 64, as well as published games like "Go!  Go!  Tank", on the Nintendo Game Boy, "Super Cars" and "Ghoul School" for the Nintendo Entertainment System, "Vortex" and "Jim Power: Lost Dimension in 3D" for the Super Nintendo Entertainment System, and "Brain Battler", "Brain Bender", "Daffy Duck: Fowl Play", "Go!  Go!  Tank and Kingdom Crusade" for the Game Boy and Game Boy Color.  They only developed one game, Trax, a side scrolling shooting game, on the Nintendo Game Boy in 1991.  In 1998, Electro Brain filed for bankruptcy and closed down after the company published their last two games, which were on the Nintendo 64, Star Soldier: Vanishing Earth, and Dual Heroes, that failed to gain revenue for the unsuccessful company.

Ellie (The Last of Us): Ellie is a fictional character in the 2013 video game "The Last of Us", and the main protagonist of the upcoming video game "The Last of Us Part II".  In the first game, the character Joel is tasked with escorting Ellie across a post-apocalyptic United States in an attempt to create a potential cure for an infection to which Ellie is immune.  She is voiced by Ashley Johnson, who also provided motion capture for the character.  While players briefly assume control of Ellie for a portion of the game, the computer's artificial intelligence primarily controls her actions, often assisting in combat by attacking or identifying enemies.  Ellie reappeared as the sole playable character in the downloadable content prequel campaign, "", in which she spends time with her friend Riley.  Ellie is also the main character in the comic book prequel, "", wherein she befriends Riley and has her first encounter with the rebel group the Fireflies.

ERE Informatique: ERE Informatique was one of the first French video game companies, founded in 1981 by Philippe Ulrich and Emmanuel Viau.  The company hired freelance game programmers that received royalties for their creations.  Initially, the company published titles for the Amstrad CPC, Spectrum and Oric home computers.  In 1984 they published their first national hit, a flight simulator created by Marc André Rampon: "Intercepteur Cobalt" for Sinclair ZX81 and Spectrum, also known under the name of "Mission Delta" for Oric, Amstrad and Thomson MO5.  Rampon also acquired some shares of the company owned by Viau and established the company's first distribution network.

Desmond Miles: Desmond Miles is a fictional character and the main protagonist of the frame story uniting the first five installments in the "Assassin's Creed" series of video games.  He is a descendant of a long line of other Assassins, including Aquilus, Altaïr Ibn-La'Ahad, Ezio Auditore da Firenze, Edward Kenway, and .  Miles is voiced by Nolan North and is modeled after Canadian fashion model Francisco Randez.

Travis Touchdown: Travis Touchdown is a video game antihero and the main protagonist of the video game franchise "No More Heroes".  27 years old in the original game, he is both an otaku and a professional assassin, wielding a Beam Katana.  He was created by Goichi Suda, and voiced by Kazuya Nakai in Japanese and Robin Atkin Downes in most English-language appearances.  He later appeared in the 2010 video game "", and will reappear in the upcoming 2018 video game "".

Open-source video game: An open-source video game, or simply an open-source game, is a video game whose source code is open-source.  They are often freely distributable and sometimes cross-platform compatible.

Supporting paragraphs: Altaïr Ibn-La'Ahad Assassin's Creed (video game)
Answer: Ubisoft