Microsoft’s new “topological qubit” is not based on a solid, liquid or gas. It is another phase of matter that many experts did not think...

Mira Murati, who left OpenAI last year, has helped establish Thinking Machines Lab, a new artificial intelligence start-up.

Bret Taylor, the chairman of OpenAI’s board, said the artificial intelligence company was “not for sale.” Mr. Musk and other investors had offered $97.4 billion...

In a court filing, Mr. Musk said he and other investors would pull their $97.4 billion bid if OpenAI withdrew its plan to change its...

The Chinese start-up used several technological tricks, including a method called “mixture of experts,” to significantly reduce the cost of building the technology.

The tool, called Deep Research, arrives days after OpenAI released another one, which shops for groceries and books restaurant reservations.

How did a little-known Chinese start-up cause the markets and U.S. tech giants to quake? Here’s what to know.

The new tool, called Operator, can shop for groceries or book a restaurant reservation. But it still needs help from humans.

The artificial intelligence start-up said the new system, OpenAI o3, outperformed leading A.I. technologies on tests that rate skills in math, science, coding and logic.

Google unveiled an experimental machine capable of tasks that a traditional supercomputer could not master in 10 septillion years. (That’s older than the universe.)