Question: Science and Industry is a mod for the video game developed by which company?
Context: League of Legends (abbreviated LoL) is a multiplayer online battle arena video game developed and published by Riot Games for Microsoft Windows and macOS.  The game follows a freemium model and is supported by microtransactions, and was inspired by the "" mod, "Defense of the Ancients". Half-Life (stylized as HλLF-LIFE) is a science fiction first-person shooter video game developed by Valve, released in 1998 by Sierra Studios for Microsoft Windows.  It was Valve's debut product and the first in the "Half-Life" series.  Players assume the role of Dr. Gordon Freeman, who must fight his way out of a secret research facility after a teleportation experiment goes disastrously wrong, fighting enemies and solving puzzles. Avalon Heroes, known as Avalon Online in Asia, is a free-to-play multiplayer online battle arena video game developed by WeMade Entertainment for Microsoft Windows.  The game is heavily based on s popular mod Defense of the Ancients.  "Avalon Heroes" did get a bit of attention in eSports circles.  The game was closed on 8 February 2013 due to not having enough active players. Science and Industry is a multiplayer, teamplay mod for the video game "Half-Life".  It is one of the oldest "Half-Life" mods and has been described as a classic one.  The current version of the game is 1.3 beta 8, released on September 17th, 2016.  The game was first publicly released on July 31, 1999, as version 0.94. Game Dev Story is a simulation video game developed and published by Kairosoft for Microsoft Windows, iOS, and Android.  It was released for Windows in April of 1997 , for iOS and Android on October 9, 2010, and for Windows Phone on July 6, 2015.  The game follows a player-controlled video game company and its attempts to expand into a sales powerhouse over time.  As a simulation, the game and the direction of the company is controlled by the player, following a parallel timeline of the video game industry and its history.  The game was released to positive reviews, with many reviewers focusing on "Game Dev Story"' s addictive aspects and its witty references to video game pop culture. Battlefield 1942 is a first-person shooter video game developed by Digital Illusions Creative Entertainment and published by Electronic Arts for Microsoft Windows and Mac OS X.  The game can be played in single-player mode against the video game AI or in multiplayer mode against players on the Internet or in a local area network.  It is a popular platform for mod developers, with a large number of released modifications that alter the gameplay and theme. Dota 2 is a free-to-play multiplayer online battle arena (MOBA) video game developed and published by Valve Corporation.  The game is the stand-alone sequel to "Defense of the Ancients" ("DotA"), which was a community-created mod for Blizzard Entertainment's "" and its expansion pack, "".  "Dota 2" is played in matches between two teams of five players, with each team occupying and defending their own separate base on the map.  Each of the ten players independently controls a powerful character, known as a "hero", who all have unique abilities and differing styles of play.  During a match, the player collects experience points and items for their heroes in order to successfully fight the opposing team's heroes, who are doing the same.  A team wins by being the first to destroy a large structure located in the opposing team's base, called the "Ancient", which is guarded by defensive towers. Driftmoon is a 2013 adventure roleplaying video game developed by Instant Kingdom.  The game also contains a built-in mod editor. Team Fortress 2 (TF2) is a team-based multiplayer first-person shooter video game developed and published by Valve Corporation.  It is the sequel to the 1996 mod "Team Fortress" for "Quake" and its 1999 remake, "Team Fortress Classic".  It was released as part of the video game bundle "The Orange Box" in October 2007 for Microsoft Windows and the Xbox 360.  A PlayStation 3 version followed in December 2007.  The game was released for Windows as a standalone entry in April 2008, and was updated to support OS X in June 2010 and Linux in February 2013.  It is distributed online through Valve's digital retailer Steam, with retail distribution being handled by Electronic Arts. Day of Infamy is a multiplayer tactical first-person shooter video game developed and published by New World Interactive set during the events of World War II in the European Theater.  It is a standalone to the "Day of Infamy" mod released for their previous title, "Insurgency".  "Day of Infamy" uses Valve's Source engine.  The game was released for Microsoft Windows, OS X, and Linux on 23 March 2017.
Answer: Valve