kvm-simple-init can perform the following actions on a KVM machine: start, stop, kill, and restart. It focuses on simplicity, and is fully implemented in just a few hundred lines of shell script. It is intended for people who do not want to run libvirt just for running a few VMs, or people who prefer to manage flat configuration files using their preferred configuration management system. It does not provide complicated configuration file format or parameters. Only two pieces of information are needed: a QEMU monitor port for the machine and the full KVM command line needed to start the machine (gives full configuration freedom). kvm-simple-init can be used directly as a system init script for starting all KVM machines on a host machine. Just drop it in /etc/init.d, and enable it with the tools provided by your UNIX distribution. kvm-simple-init was inspired by the init script of FreeBSD jails.
libguestfs is a set of tools for accessing and modifying virtual machine (VM) disk images. You can use this for viewing and editing files inside guests, scripting changes to VMs, monitoring disk used/free statistics, P2V, V2V, performing partial backups, cloning VMs, and much more. libguestfs can access nearly any type of filesystem including: all known types of Linux filesystem (ext2/3/4, XFS, btrfs, etc.), any Windows filesystem (VFAT and NTFS), any Mac OS X and BSD filesystems, LVM2 volumes, MBR and GPT disk partitions, raw disks, qcow2, CD and DVD ISO images, SD cards, and dozens more. libguestfs doesn't need root permissions.
rConfig is a network device configuration management utility for network engineers to take frequent configuration snapshots of their network devices. It lets you choose which commands you want to run against your devices. Simply configure rConfig with the list of commands you wish to apply to a category of devices, and add devices to the category. Create a scheduled task, and rConfig will do the rest.
rules2mrtg is a tool that creates MRTG data traffic graphs derived from iptables's internal traffic statistics for the local machine for every configured IP number/ethernet alias. You can also define ports or port ranges to be monitored per IP address. This avoids problems with using SNMP and aliased interfaces.