1. Companies starting with T:

      Tachyon Studios
      Taito
      Takara
      Take 2
      TaleWorlds Entertainment
      TalonSoft
      Tandem Games
      Tapulous
      TCKSoft
      TDK
      Team 47
      Team Bondi
      Team Ninja
      Team Terminator
      Team17
      TeamTerminator
      Techland
      Technos
      Tecmo
      Tehkan
      Telltale
      TenGen
      Terminal Reality
      Texasoft
      That Game Company
      The Cornsoft Group
      The Game Equation
      The Learning Company
      The Liberty Software Company
      The Micro Works
      The Programmer's Guild
      The Software Farm
      Thesis
      THQ
      Three-Sixty
      Thunder Mountain
      Tikgames
      Tilted Mill Entertainment
      TimeGate
      Titus
      Tom Mix Software
      Tommo
      Tomy
      Tonka
      Tonuzaba Entertainment
      Torpedo Software
      Torus Games
      Torus
      Tose
      Totally Game
      Toucan Software
      Touchstone
      Toys For Bob
      Tozai Games
      Tradewest
      Traveler's Tales
      Traveller's Tales
      Treasure
      TreeCardGames
      Trend Software
      Trendy Entertainment
      Treyarch
      Tri Synergy
      Tri-Ace
      Trilobyte
      Tripwire Interactive
      Triumph Studios
      Troika
      Trygames
      Trymedia
      TT Games
      Turbine
      Twilight Games
      Twisted Pixel Games
      Two-Bit Software
      Typhoon Games

      Note: bolded names indicate companies that released a game within the last twelve months.