INDIGO is a framework for the control of, and communication with, telescope equipment and accessories. It is based on the same underlying protocol as INDI but it has been rewritten to make it more robust and more efficient.
I have been using INDIGO for my variable star photometry for the past year and really like it (I've tried INDI as well). It can be used for deep sky photography just was well.
Rumen, one of the primary INDIGO developers, is going to give a YouTube Live presentation entitled "Introduction to the INDIGO Framework" this Sunday evening (at least for the US).
https://www.youtube....h?v=ko1Qjs9Zdes
If you have any interest, it will be worth tuning in.
You can also learn more about INDIGO here: https://www.indigo-a....org/index.html
here: https://www.indigo-a.../for-users.html
and in this FAQ: https://www.indigo-a...my.org/faq.html
Bill