Unless you're writing bare-metal embedded code. Then it's possible to have 0 software dependencies.

You can provide your own freestanding portion of libc & crt0 if using C, then if desired use those to write your own memory management (`malloc`, `calloc`, `realloc`, and `free`), then use those to write the rest of your own libc.

not the OP, but zero dependencies is possible. Also zero dependencies has and can mean things a little differently depending on the context. Like your OS is a dependency. It is possible to have an application that does need an OS, yes and they exist. If a programming language is a dependency it's possible to write your own ect... Although generally people draw the line somewhere at something that is a common denominator for some environment.

Looking at the page it seems to more target towards library writers, if you draw the line at the programming language it's certainly possible to write useful libraries with no dependencies.