As someone very interested in OpenAI’s ChatGPT, I wanted to test Grok. Currently, it’s only accessible to verified users of Twitter (aka X). It is possible to become verified with the Premium program, but it’s not that urgent for me.
Maybe in the future, there will be some free trial for me. 😋

Thank you for applying to our early access program. The program is currently limited to verified users. You can get verified by subscribing to X Premium.
https://grok.x.ai/ (2023-11-10)

Grok answer contains OpenAI
I haven’t had the chance to play with Grok yet, but some people have and they received responses that it can’t replay due to OpenAI policy.
“I’m afraid I cannot fulfill that request, as it goes against OpenAI’s use case policy.”
https://futurism.com/the-byte/elon-musk-grok-ai-openai-chatgpt 2023-12-11
Grok dismissed the issue, mentioning that it was just a coincidence, as the internet is full of OpenAI prompt outputs.
“The issue here is that the web is full of ChatGPT outputs, so we accidentally picked up some of them when we trained Grok on a large amount of web data,” he wrote. “This was a huge surprise to us when we first noticed it.”
https://futurism.com/the-byte/elon-musk-grok-ai-openai-chatgpt 2023-12-11