Torta shows you where your disk space is going. It uses the graphical format used by filelight to represent disk usage. Unlike filelight, it can be run on a computer with no graphical environment: it generates a Flash file that can be consulted, locally or remotely, using any browser that has the Flash plugin installed.
Python Tracer lets you see your Python program's execution as a tree of function invocations, each tree node exposing the real time and CPU time (user/sys) of that call. The project consists of two main components: a Python tracer that can run your Python programs (much like "cProfile" and friends), and a GTK+ based GUI that can show the trace results. It uses a tiny auxiliary library (graphfile) to allow append-only writing and reading static DAGs directly from a file without reading it whole into memory at any stage.
BigDaddy is a program for monitoring servers. It is similar to Nagios, with the added benefit of also monitoring and controlling the crontab (or any scheduled application) across an entire fleet of servers. The application comes in the form of a daemon for monitoring and reporting as well as an easy-to-use Web-based GUI for controlling monitoring, viewing timelines of incidents, filing incidents and graphing statistics. The application is extensible with any sort of monitoring module and notification is based on a five step escalation process.
mod_top is a production monitoring tool for LAMP applications with user interfaces modeled after the popular Unix top. It plans to support PHP, Perl, Ruby, Python, mySQL, PostgreSQL, and Apache 1 and 2 on Linux. It can help you locate bottlenecks in applications, troubleshoot high memory consumption, understand CPU utilization under load, diagnose causes of slowness or heavy resource utilization, or discover database dependencies.
iloog is a Gentoo-based live CD targeted mainly at students and scientists. It features UnionFS filesystem support that enables you to write everywhere on the LiveCD and install extra packages, a graphical X environment through the Fluxbox window manager, many programming editors and IDEs, and a plethora of scientific applications, including Octave, Namd, Merlin, and full (La)TeX support.