Sequencer is an engine used by system administrators for the computation and execution of sequences of actions over hardware or software. It can ping various devices in parallel, power on your whole cluster, or generate an Emergency PowerOff (EPO) script for your data center or cluster. It takes into account various dependencies (power off nodes before switches, clients before server), deals with failures kindly, and is very efficient (>4000 nodes in less than 10 minutes).
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.
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.