What languages is Open Assistant written in?
The core of Open Assistant is written in Python, but it uses libraries and connects to tools written in a variety of languages. The source code for Open Assistant is available on GitHub for anyone to view and edit: https://github.com/LAION-AI/Open-Assistant
Could I run OpenAssistant on my machine?
Depends on what machine you have.
But
1) The model as well as everything else is open source. So in principle you could
2) Right now (2023) the hardware to run a large model is still expensive. But the very fast improvements we have seen in the last years are not going to slow down. So the answer might very well be yes soon.