Microsoft says it is making a “multiyear, multibillion dollar investment” in the artificial intelligence startup OpenAI, maker of ChatGPT and other tools that can write readable text and generate new images.

The tech giant today described its new agreement as the third stage of a growing partnership with San Francisco-based OpenAI that began with a $1 billion investment in 2019. It didn’t disclose the dollar amount for its latest investment.

OpenAI’s free writing tool ChatGPT launched on Nov. 30 and has brought public attention to the possibilities of new advances in AI.

It’s part of a new generation of AI systems that can converse, generate readable text on demand and even produce novel images and video based on what they’ve learned from a vast database of digital books, online writings and other media.

OpenAI started out as a nonprofit artificial intelligence research company when it launched in December 2015. With Tesla CEO Elon Musk as its co-chair and among its early investors, the organization’s stated aims were to “advance digital intelligence in the way that is most likely to benefit humanity as a whole, unconstrained by a need to generate financial return.”

That changed in 2018 when it incorporated a for-profit business Open AI LP, and shifted nearly all its staff into the business, not long after releasing its first generation of the GPT model for generating human-like paragraphs of readable text. Musk also left its board in 2018.

OpenAI is also the creator of the DALL-E tool for generating new images.

Microsoft said today its strengthened partnership can help “to accelerate AI breakthroughs to ensure these benefits are broadly shared with the world.”