Every now and then I like to set up a Linux instance in VMware to try out new software or to have a sandbox for development. Lately, I've found that ArchLinux has some nice features that make it perfect for that kind of setup.
First, it's unobtrusive. you get a bare basics environment and nothing else. The base install includes little other than the essential packages and lets you build from there. It's minimal and lightweight with install ISO's weighing in at around 360MB and the netinstall ISO's just under 180MB.
When you need more than the base install, Arch Linux has a package system called pacman, which is a breeze to use. Installing a package often involves little more than executing
sudo pacman -S <package name>
And since it's is on a rolling release cycle, there's no need to wait for the next release of Ubuntu to get the latest packages. Configuration is done via text files; adding services to run at start up requires just an edit to /etc/rc.conf. If you need to build packages, Arch Linux provides the Arch Build System, which is a ports-like build system. If you can script in bash, you can build a package.
Good documentation is also available straight from their site. You don't need to troll through dozens of forums to figure out how to get something installed, you go straight to their wiki, where there are guides on everything from the basic installation procedure to setting up Linux containers. The wiki also hosts translations of these guides in a variety of languages, which I imagine would be helpful for non-native English hackers.
Arch Linux reminds me a lot of my first Linux distro, Slackware. Both are minimalist, functional, and allow the user to maintain a lot of control over the system. There isn't much hidden behind the curtain. Arch Linux, however, throws in a packaging system and more current packages. Getting it set up and running couldn't be easier. For that, it earns a place in my toolbox.