1. Companies starting with H:

      Haemimont
      Haggard Games
      Hanako Games
      Handmark
      Handy Games
      Happy Happenings
      Harebrained Schemes
      Harmonix
      Hasbro
      Havas
      Hayden Book Company
      Head Games
      Headfirst
      Heavyreign
      Henize Software
      Her Interactive
      Hewson
      Hidden Sanctum
      High Moon Studios
      High Voltage
      HipSoft
      Hi-Tech Expr.
      HMI
      Honeysoft
      HopeLab
      Horizons
      Horrorsoft
      Housemarque
      Howard W. Sams & Company
      Hudson Soft USA
      Hudson Soft
      Human Code
      Humanhead
      Humongous Entertainment
      Hussar Games
      Hyperkat Games
      Hypnotix

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