You can view the current implementation status of the WebDriver standard here.
Latest ChromeDriver Binaries
Starting with M115 the latest Chrome + ChromeDriver releases per release channel (Stable, Beta, Dev, Canary) are available at the Chrome for Testing availability dashboard. For automated version downloading one can use the convenient JSON endpoints.
The older releases can be found at the Downloads page.
Security Considerations, with recommendations on keeping ChromeDriver safe
The chromedriver-users mailing list for questions, help with troubleshooting, and general discussion.
All code is currently in the open source Chromium project. This project is developed by members of the Chromium and WebDriver teams.