supervisor - PHP CLI process supervisor, based on Symfony/Process
pgBackRest aims to be a simple, reliable backup and restore system that can seamlessly scale up to the largest databases and workloads.
Postgres EXPLAIN Visualizer - designed to make EXPLAIN output easier to grok. It creates a graphical representation of the plan.
supervisor - PHP CLI process supervisor, based on Symfony/Process
Using Elementary OS 0.3 Freya daily build for two days. Not ideally stable (it is not even beta), but beautiful :) Btw. Beta status could be tracked in http://isfreyareleasedyet.com/.
Runnable.com - jsFiddle alternative for server side (PHP, Ruby, Bash and even much more) languanges. Allows to run, share and collaborate on code snippets.
bouncejs allows to make nice CSS3 animations composition via GUI
vtop - Node.js based htop replacement. Looks very nice, but I dont think I will use it on real server.