A Bash script for installing ArchLinux automatically. Right now I'm finishing a "system" for setting up the partitioning scheme (with MBR). You just store partition data in each row of a matrix (type, size, label, mount point, etc), with each row representing a partition. It takes row order as partition order (so row 0 is the first partition, row 1 is the second, and so on). This is the hardest thing to automate in pre-installation and is not difficult to do. It's fun because you have to catch errors like defining logical partitions after primary non-extended ones, partition sizes exceeding disk size and simple stuff like that, it's relaxing.