Here are the classes, structs, unions and interfaces with brief descriptions:
  Axis | Msgs::Joint axis message |
| BoxGeom | Information about a box geometry |
| CameraCmd | Message for camera command |
| CameraSensor | Information about a camera sensor element |
| Collision | Information about a collision element |
| Color | Color message |
| Contact | Contact message for passing info between two entities |
| Contacts | Contacts from collision detection |
| ContactSensor | Information about a contact sensor element |
| CylinderGeom | Information about a cylinder geometry |
| Diagnostics | Diagnostic information about a running instance of Gazebo |
| Factory | Message to create new model in gazebo |
| Fog | Message for fog data |
| ForceTorque | ForceTorque from constraint solving |
| Friction | Information about friction |
| Geometry | Information about a geometry element |
| GPS | Data from a GPS sensor |
| GUI | Message for a GUI |
| GUICamera | Message for a GUI Camera |
| GUIOverlayConfig | Message for a gui overlay configuration |
| GzString | A message for string data |
| GzString_V | A message for a vector of string data |
| Header | General information included by many messages |
| HeightmapGeom | Message for a heightmap geometry |
| Image | Message for an image |
| ImageGeom | Message for a image geometry |
| ImagesStamped | Message for a multiple image with a time |
| ImageStamped | Message for an image with a time |
| IMU | Data from an IMU sensor |
| Inertial | Information about inertia |
| Int | Integer message |
| Joint | Message for creating joint in rendering::Scene |
| JointAnimation | Message for a model joint animation, does not appear to be used |
| JointCmd | Message for joint command, used by physics::JointControlWidget |
| JointWrench | Joint wrench message |
| LaserScan | Data from a laser scan |
| LaserScanStamped | Message for an laser scan with a time |
| Light | Message for a light |
| Link | Information about a link |
| LinkData | Timestamped link data |
| LogControl | A message that allows for control of logging functions |
| LogStatus | A message that contains information about data logging |
| Material | Information about a material |
| MeshGeom | Message for a mesh geometry |
| Model | Information about a model |
| Model_V | Information about all entities in a world |
| ModelConfiguration | Message for model configuration (joint positions) |
| Packet | Message that encapsulates another message with a type description |
| Physics | A message containing a description of the global physics properties |
| PID | Message for simple PID controllers |
| PlaneGeom | Message for a plane geometry |
| Plugin | A message containing visual information for gazebo::Plugin |
| PointCloud | A point cloud |
| Pose | Message for a pose |
| Pose_V | Message for a vector of poses |
| PoseAnimation | Message for a model pose animation |
| PosesStamped | Message for a vector of poses with a time stamp |
| PoseStamped | Message for a pose with a time |
| PoseTrajectory | Message for a pose trajectory |
| Projector | Information about a projector |
| PropagationGrid | Wireless propagation grid |
| PropagationParticle | Wireless strength signal in a point |
| Publish | Message that contains information about a publisher of data |
| Publishers | A list of publishers |
| Quaternion | A message for a quaternion |
| RaySensor | Information about a ray sensor element |
| Request | A message containing a string request |
| Response | Message that encapsulates a respons message with a type description |
| Road | Message for a road |
| Scene | A message containing a description of a scene |
| Selection | A message for GUI selection data |
| Sensor | Information about a sensor element |
| ServerControl | A message that allows for control of the server functions |
| Shadows | A message for shadow data |
| Sky | Information about the sky |
| Sonar | Message for a sonar value |
| SonarStamped | Message for a time stamped sonar value |
| SphereGeom | Information about a sphere geometry |
| SphericalCoordinates | Spherical coordinates information |
| Subscribe | A message for subscription data |
| Surface | Information about a surface element |
| Tactile | Message for a tactile data |
| Test | A test message |
| Time | A message for time data |
| TopicInfo | A message for topic information |
| TrackVisual | Message for a trackking a rendering::Visual with a rendering::Camera |
| Vector2d | Message for a vector2 double |
| Vector3d | Message for a vector3 double |
| Visual | A message containing visual information for rendering::Visual |
| WirelessNode | Message for sending info about a detected wireless transmitter |
| WirelessNodes | Msgs for sending information about a list of wireless transmitters |
| WorldControl | A message that allows for control of world functions |
| WorldModify | A message that allows for modifying (open, close) worlds |
| WorldReset | A message that controls how the world is reset |
| WorldStatistics | A message statiscs about a world |
| Wrench | Message for a wrench value |
 WrenchStamped | Message for a time stamped wrench value |