Is it safe to run multiple
brew install commands at the same time?
In general, yes. There should be no problem doing that.
Homebrew will just download the files needed to brew the formula, then run the configuration and compilation by itself. This shouldn't be an issue since all formulae live in their own respective folders – except for the very rare cases when you happen to install two formulae concurrently which have the same dependency.
Ideally, I'd check a formula's dependencies with
But other than that: I do it all the time and haven't run into issues yet.