Quote: What is your favorite linux distro?
While I've futzed around with a number of distros (predominantly Ubuntu and Gentoo, some others as well), I find that Arch provides the best middle ground between ease of use and configurability. It has a very well maintained package repository (where you get all your pre-build programs from) that in my experience is much more up to date than other distros and optimized for newer processors. And if you want to go the Gentoo way and build all the software, that's easily automated too. Setup is a little more involved than Ubuntu though, since its installation leaves you with a very bare bones system (the way I like it) that you'll have to configure to taste.
If you're totally new to Linux, I'd probably recommend Ubuntu until you get your feet wet and understand the system to be able to manually configure things the way many other distros require.
Quote: What kernel is it based off of?
Currently 2.6.21.
Quote: What do you use your distro for?
Which linux distro do you use to program C/C++ programs?
It's the only unemulated OS installed on my system.
Quote: Which distro provides the most development tools?
All development tools are be build on all major distros. That's the thing about most linux tools--if there isn't a package already made for your distro, just download the source and compile it yourself.