ArduPilot has revolutionized autonomous vehicle development.  Prior to ArduPilot there were a few very expensive proprietary autopilot systems.  The open source ArduPilot project has proven that small to medium companies can grow quickly leveraging the man power of hundreds of open source developers.  By working through ArduPilot Initiative you can field your product or incorporate new features to an existing capable code base.  After integration into the codebase it is maintained by the wider open source project saving you time and money.