The reason I primarily use Linux instead of Windows, and what I imagine is a compelling reason for a lot of other people, is the GNU developer utilities (binutils, autoconf, make, etc.) and the various package managers. With no standard package management or build system for C, this makes it much easier to compile the vast amount of C projects out there. A quick search finds that Haiku uses these tools, and also has a package manager. How mature are these for C development?

This sort of purposely single-user OS is really interesting to me. I really don't need to pretend my computer needs to support many simultaneous users with various access controls. It's just me on pretty much all of my devices. As long as the OS can multitask decently (a big feature of BeOS) and I can sandbox untrusted stuff I might want to run, I'm not sure if I need anything more.

Also I'm really grateful for Haiku since it made a hand-me-down laptop which has a CPU clock speed measured in Mhz and a built in floppy drive feel snappy and useful where even Lubuntu stuttered back during one of the R1 alphas.