x11vis is a visual and interactive tool for debugging X11 clients. Unlike other tools such as xtrace, it displays human readable IDs on all requests, no matter at which point in time the information becomes available. To help you cope with large amounts of data, it displays only the most important information by default, automatically folds sequences of boring requests, allows you to filter by packet type or client, and provides markers for navigation. Instead of assigning a number to each connection, it displays the command line with which that client was started.
Spaghetti Parenthesis Visualizer is an in-browser (meaning that it doesn't send your code to a server) tool that takes deeply nested conditionals in languages that follow in C's footsteps, including Python, Perl, PHP, and Java, SQL queries, or some Lisp code, and provides two visual presentations that clearly and cleanly display how deep each part of the code is in the layers of nesting.
glNetViz is a tool for visualizing computer network topologies with WebGL. With the abilities of real time visualizing network traffics flowing around the local network and to/from the Internet, you can manage the various network more easily and efficiently. glNetViz is intended to be a convenient tool that can easily visualize the network topology from the serialized data in YAML or JSON.