Ansible is a radically simple deployment, configuration, and command execution framework. It is dead simple and painless to extend. Extending Ansible does not require programming in any particular language; you can write modules as scripts or programs which return simple JSON. It’s also trivially easy to just execute useful shell commands.
Chef is a systems integration framework, built to bring the benefits of configuration management to your entire infrastructure. With Chef, you can manage your servers by writing code, not by running commands (via Cookbooks), integrate tightly with your applications, databases, LDAP directories, and more (via Libraries), and easily configure applications that require knowledge about your entire infrastructure ("What systems are running my application?" "What is the current master database server?").
MN Viewer (Mobile Network Viewer) is a lightweight framework designed for system administrators who would like to be able to monitor many aspects of their network from their mobile phone. It allows for very simple expansion using simple PHP plugins. It is designed to integrate with other monitoring tools such as Cacti.
cronbot is a wrapper script for cron jobs. Rather than running your job/script directly, you run it through cronbot, and it will allow a little more control to help keep things from getting out of hand. The default behavior is to only allow one instance of your job to run. This can be changed with the --duplicate option. You can also pass in a maximum time of execution for a job or add a random amount time to delay the start of your job. By default, jobs are run with a default "nice" value, which is usually 10.
s6-portable-utils is a set of tiny general Unix utilities, often performing well-known tasks such as cut and grep, but optimized for simplicity and small size. They were designed for embedded systems and other constrained environments, but work everywhere. Other sets of small utilities are usually system-specific; for instance, the (otherwise excellent) BusyBox project only works on Linux.
sysfunc is a shell library intended for Unix sysadmins. It provides a set of portable shell functions including features such as file copy, symbolic link management, file/dir deletion, user/group management, data block replacement in a file, line replacement, commenting/uncommenting lines, service management, and volume group/logical volume/file system creation.