Llama and Stable Diffusion are the most popular alternatives.
Llama is nowhere close to chatGPT but good enough for some users. Stable diffusion 2.1 is better than Dalle2. There is an experimental version of dalle only accessible to a few selected people that seem better than stable diffusion 2.1 though. MidJourney is a bit better but not Open-source and you will not be able to generate some kind of pictures. Which could be a good thing perhaps.