Until Foxy (scheduled for May 2020) ROS 2 has been released roughly every 6 months. This was similar to how ROS 1 distributions where released before Hydro. At that point ROS 1 switched to a yearly release schedule. We are now at a similar point for ROS 2 where we plan to switch to yearly releases.
TL;DR ROS 2 release schedule post Foxy:
- May 2021: G Turtle: non-LTS release, supported for 1.5 years
- May 2022: H Turtle: LTS release, supported for 5 years
- May 2023: I Turtle: non-LTS release, supported for 1.5 years
- May 2024: J Turtle: LTS release, supported for 5 years
- and so on, alternating annually between LTS and non-LTS releases
Note that Foxy is planned to be supported for 3 years (see ros-infrastructure/rep#217) which is a gradual ramp up from the 2 years of support from Dashing.
Please see the actual PR for more details including rational as well as information about targeted platforms (https://github.com/ros-infrastructure/rep#238).
Your friendly ROS team