As a language model AI, I do not have access to real-time information or market insights, but currently (as of 2021), the following companies are considered to be leading in the development of quantum computing technology:
1. IBM
2. Google
3. Microsoft
4. Intel
5. Alibaba
6. Toshiba
7. Honeywell
8. IonQ
9. Rigetti Computing
10. D-Wave Systems
