The changelogs for MoveIt can be found directly on the MoveIt ROS Wiki page. Announcements on the mailing list also inform users of the latest changes.
Terminology
What is the difference between MoveIt 1 and MoveIt 2?
MoveIt 2 is currently (April 2020) a straight port of MoveIt 1 but for ROS 2.
ROS 2 is a total rewrite of the popular robotics middleware that addresses many unfulfilled needs of industry / commercial users in ROS 1.
MoveIt 2 will hopefully fork from MoveIt 1 soon to take advantage of the new features in ROS 2. See the roadmap.
What is the difference between MoveIt and ROS?
MoveIt runs on top of ROS (Robot Operating System).
ROS is an open-source meta-operating system for robots that provides low-level functionality like a build system, message passing, device drivers and some integrated capabilities like navigation.
MoveIt is a primary source of the functionality for manipulation (and mobile manipulation) in ROS.
MoveIt builds on the ROS messaging and build systems and utilizes some of the common tools in ROS like the ROS Visualizer (Rviz) and the ROS robot format (URDF).
MoveIt is a common entry point into ROS, especially through the use of the MoveIt Setup Assistant for configuring new robots.
What is the difference between MoveIt and OMPL?
OMPL is an open-source motion planning library that is used by MoveIt for motion planning.
MoveIt uses an extensible plugin architecture and other motion planning libraries can also easily be integrated with MoveIt.
OMPL provides a variety of high-quality well-tested randomized planners.
What is the difference between MoveIt and PickNik?
MoveIt is an open source project that started at Willow Garage (see history) and is now led by PickNik Robotics.
PickNik was founded by lead MoveIt maintainer Dave Coleman with the mission of growing the MoveIt project through community building and contract consulting.
What is the difference between MoveIt and ROS-Industrial?
The ROS-Industrial consortium aims to use the advanced tools in MoveIt and ROS to build and demonstrate advanced applications in industry.
ROS-Industrial also develops and maintains ROS drivers for industrial robots.
Bugs/Issues
I have a fix for a bug in the MoveIt tutorials. What should I do?