Considering C99 for Curl
The tipping point for me would be `snprintf()` and related functions. I've found it generally more useful/memorable/readable than strncpy()/strlcpy() and other updates to the dangerous and deprecated strcpy() just for copying strings safely, never mind it's other formatting abilities.<p>If Curl already has its own "decent and functional replacement" for `snprintf()` that's used extensively throughout the codebase, or if they just don't need that functionality (I haven't checked) then I guess that's not an issue. But that would be the big selling point as far as I'm concerned.