None; it's an optional package you use when your users require FIPS 140.

Ahh okay I didn’t realise it is just a package. I wondered if it was more than that and included stuff with the compiler or something

It's also a new compiler option to transparently replace calls to the crypto stdlib package with FIPS versions

It means companies with US government contracts writing Go code can use the standard library crypto package in native Go instead if having to enable CGO and using a crypto library written in C. CGO is kind of a pain in the ass to develop with compared to fully native Go code, especially when cross-compiling (and cross compilation is very common now that ARM is common on both laptops and servers).

This also now makes Go a very convenient language to write US Gov software in.

If you have never heard of FIPS before ignore this entirely and continue to live in happiness.

> This also now makes Go a very convenient language to write US Gov software in.

This is something I wondered. Will we now see even more adoption of Go? Will Go be a more attractive option compared to language X/Yv

Yeah, honestly, this just rocketed Go to possible one of the best languages to write these services in. You can write a fully self-contained and compliant program using just the standard library, where a lot of other languages need to be linked to a commercial SSL library.