demo

Inigo Quilez live-paints a mountain landscape using only math in a shader, building up from a basic polynomial noise surface through fractal terrain, lighting and atmosphere. The code runs in real time on Shadertoy so viewers can edit it as they follow along.

Tech Ingredients shows how to build a liquid panel with a specialty paint that, placed outside, cools below ambient air temperature. It demonstrates radiative sky cooling.

Dodoid gives an in-depth look at an SGI Onyx RealityEngine2, a $250,000 graphics supercomputer from 1993, covering its history, a physical overview, a teardown and some demos and games.

Loopop reviews the Polyend Tracker hardware tracker-style sequencer and walks through a tutorial from sampling to finishing a song. It covers most of the device's features.

Tech Ingredients builds a pair of large Voigt speakers and explains ported, transmission line and horn designs. It tests them in an anechoic chamber and uses constrained layer damping for the enclosure.

Russ Cox gives a 23-minute tour of the Acme text editor from Plan 9, showing its mouse-driven interface, executing commands from text, and its filesystem-based interface to other programs.

Ben Krasnow of Applied Science explains how electrophoretic e-paper displays work and how he modified the driver firmware and waveform lookup tables of a 4.2-inch panel to reach roughly 3Hz partial refresh. It covers the tweakable constants in the refresh process and touches on colored e-ink microcapsules.

Ben Vallack walks through designing a custom keyboard PCB from scratch using Ergogen and KiCad, ending with a gerber file ready to order from a PCB fabricator. The example is a split keyboard.

A screencast tutorial on Specter, a Clojure library for navigating and transforming nested data structures declaratively, demonstrated in a REPL.

Allieway Audio gives an informal introduction and live-coding demo of ORCA, a free esoteric programming environment for building procedural sequencers from Hundred Rabbits. It walks through the interface and how to make music with it.

Tech Ingredients shows how to make a homemade radiative cooling paint, with a custom liquid panel that cools below ambient temperature outdoors. The video covers the materials and how to apply the paint.

NightHawkInLight shows how to make ultra-white radiative paint that cools surfaces below ambient temperature without electricity. He walks through the research papers and the household-materials process.

George Brocklehurst of thoughtbot demonstrates Vim's built-in completion mechanisms, from word, line and block completion to ctags. The aim is to type less and make fewer typos.

Harry Schwartz gives a roughly hour-long tour of Emacs Org mode as an outliner, task manager, markup language and agenda tool. He demonstrates how he uses it for documents, presentations and todo lists.

A walkthrough of installing Synapse, Riot and Jitsi from scratch on Debian to run your own Matrix communication service. The description warns it is now quite outdated and links to updated material.

Marco Baringer's tutorial video on SLIME, the Emacs mode for developing Common Lisp. It demonstrates the interactive workflow of working against a live Lisp image.