zld
A faster version of Apple's linker
...Personally, I'd use it in projects with an existing link time of even 500ms (but I am an impatient tinkerer). zld is forked from the most recently open-sourced version of ld. It's used by thousands of developers across many of the largest apps in the world. Without a few optimizations around hashing, it would produce byte-for-byte the same executables as the open-source one.