Thanks for your answer 😉Yes, I already use Xcode for my C, Swift, Java, Python and HTML / JS projects. In fact, I'm trying to make Xcode my main IDE.Now, I would like to create my LaTeX documents with it. I could edit the Scheme to make it use `pdflatex` with the right arguments.The only things missing would be syntax coloring and auto-completion.I read docs and tutorials about Xcode Source Editor Extension you suggested me. But it doesn't seem to allow me to edit the syntax coloring.I saw a project already exists to use LaTeX on Xcode but it's latest supported version is Xcode 5... The project use "xclangspec" and "xcsynspec" files which seem to tell Xcode the syntax and how to color it. But it seems that those files cannot be use with Xcode 11, I didn't find quite anything about it on web.

The xclangspec was the key, there isn't any documentation but by reading similar project for other language and the built-in file, I manage to do what I wanted. So I create a repo to add Latex support for Xcode : LaTeX-for-Xcode - https://github.com/valentindusollier/LaTeX-for-Xcode.