ROS-contributed packages are indexed on the official website at http://www.ros.org/browse/list.php.
As of July 2018, ROS Indigo (the distribution released for Ubuntu 14.04 LTS) has more than 2,900 packages, while ROS Kinetic (2016, Ubuntu 16.04 LTS) has over 1,600. Some of the more popularly downloaded ones include the following:
- rviz (http://wiki.ros.org/rviz): The 3D visualization tool for ROS. You will start using this in Chapter 4, Creating the Virtual Two-Wheeled ROS Robot.
- gazebo_ros_pkgs (http://wiki.ros.org/gazebo_ros_pkgs): This allows you to use the Gazebo 3D simulator from inside ROS. We will introduce Gazebo in Chapter 5, Simulating Robot Behavior with Gazebo.
- sensor-msgs (http://wiki.ros.org/sensor_msgs): This is a package that defines messages for commonly used sensors, such as cameras and scanning laser rangefinders.
- tf2...