You're reading the documentation for an older, but still supported, version of ROS 2. For information on the latest version, please have a look at Humble.
Ardent Apalone (
Table of Contents
Welcome to the first non-beta release of ROS 2 software named Ardent Apalone!
This version of ROS 2 is supported on three platforms:
Ubuntu 16.04 (Xenial)
Mac macOS 10.12 (Sierra)
Distributed discovery, publish / subscribe, request / response communication
Provided by a C API
Implemented using different vendors:
eProsima’s Fast RTPS as well as ADLINK’s OpenSplice (from binary and source)
RTI’s Connext (only from source)
Numerous quality of service settings for handling non-ideal networks
DDS Security support (with Connext and Fast RTPS)
C++ and Python 3 client libraries
Sharing common code in C to unify the implementation
Execution model separated from the nodes, composable nodes
Node-specific parameters (only in C++ atm)
Life cycle (only in C++ atm)
Optionally intra-process communication using the same API (only in C++)
Message definitions (with bounded arrays and strings as well as default values)
Command line tools (e.g.
rvizwith a few display types (the Windows version will likely follow in a few weeks)
File system-based resource index (querying information without recursive crawling)
Realtime safe code paths for pub / sub (with compatible DDS implementations only)
Bridge between ROS 1 and ROS 2
HSR demo see Beta 3
Turtlebot demo see Beta 2
For a more detailed description please see the Features page.
Improvements since the Beta 3 release:
Different initialization options for message data structures in C++ (see design doc)
Logging API improvements, now also used in the demos
Time support in C++ with different clocks
wait-for-service support in the Python client library
Draft implementation of REP 149 specifying format 3 of the package manifest files
Fast RTPS performance with larger data like the image demo
Using Connext it is currently not allowed for two topics with the same base name but different namespaces to have a different type (see issue).
Listing of node names (e.g. using
ros2 node list) does not work across some rmw implementations.
On Windows Python launch files might hang when trying to abort using
Ctrl-C(see issue). In order to continue using the shell which is blocked by the hanging command you might want to end the hanging Python process using the process monitor.