As of 2021, here are 10 tech companies that are leading in the development of autonomous vehicles and self-driving car technology:

1. Waymo (Alphabet Inc.): An autonomous driving technology subsidiary of Alphabet Inc. (Google) that is widely considered a pioneer in the field.

2. Tesla: Known for its electric vehicles, Tesla is a significant player in the self-driving technology domain with its Autopilot system.

3. Cruise (General Motors): A self-driving car company acquired by General Motors, focusing on developing and deploying autonomous vehicle technology.

4. Zoox (Amazon): Acquired by Amazon in 2020, Zoox is an autonomous vehicle start-up working on creating a fleet of fully autonomous, purpose-built taxi vehicles.

5. Mobileye (Intel): An Intel-owned company specializing in computer vision and collision avoidance systems, providing technology for advanced driver-assistance systems (ADAS) and autonomous driving.

6. Argo AI (Ford and Volkswagen Group): Backed by Ford and the Volkswagen Group, Argo AI develops self-driving technology, including software, sensors, and hardware.

7. Aurora: A self-driving technology company partnering with automakers like Volkswagen, Hyundai, and Volvo to develop autonomous vehicle systems.

8. Uber ATG (Advanced Technologies Group): Formerly Uber’s self-driving car division, it was acquired by Aurora in 2020. Uber ATG was at the forefront of developing autonomous ride-sharing technology.

9. Baidu: Often referred to as the “Google of China,” Baidu is a leading Chinese search engine that has been investing heavily in autonomous vehicles and self-driving technology.

10. NVIDIA: A graphics processing unit manufacturer that provides processors and software platforms for autonomous vehicles. NVIDIA’s Drive platform is utilized by numerous companies working on self-driving technology.

It’s worth mentioning that the autonomous vehicle industry is constantly evolving, and the state of leadership can change rapidly as companies progress in their development efforts.