PPO2

Original paper: https://arxiv.org/abs/1707.06347
Baselines blog post: https://blog.openai.com/openai-baselines-ppo/
python -m baselines.run --alg=ppo2 --env=PongNoFrameskip-v4 runs the algorithm for 40M frames = 10M timesteps on an Atari Pong. See help (-h) for more options.
python -m baselines.run --alg=ppo2 --env=Ant-v2 --num_timesteps=1e6 runs the algorithm for 1M frames on a Mujoco Ant environment.
also refer to the repo-wide README.md