Description of various licenses for open hardware.

youtube-dl is a command-line program to download videos from YouTube.com and a few more sites. It requires the Python interpreter (2.6, 2.7, or 3.2+), and it is not platform specific. We also provide a Windows executable that includes Python. youtube-dl should work in your Unix box, in Windows or in Mac OS X. It is released to the public domain, which means you can modify it, redistribute it or use it however you like.

PDF Tools is, among other things, a replacement of DocView for PDF files. The key difference is, that pages are not pre-rendered by e.g. ghostscript and stored in the file-system, but rather created on-demand and stored in memory.

This rendering is performed by a special library named, for whatever reason, poppler, running inside a server program. This program is called epdfinfo and its job is it to successively read requests from Emacs and produce the proper results, i.e. the PNG image of a PDF page.

Actually, displaying PDF files is just one part of PDF Tools. Since poppler can provide us with all kinds of information about a document and is also able to modify it, there is a lot more we can do with it.

[shaarli save link does not work here under Firefox 45.5.1/Windows or Firefox 51.0.1 (64-bit) on xubuntu, because github does not allow "foreign" JavaScript]

WaveDrom draws your Timing Diagram or Waveform from simple textual description.
It comes with description language, rendering engine and the editor.
WaveDrom editor works in the browser or can be installed on your system.
Rendering engine can be embeded into any webpage.

Explanation of the possible states of a Linux process.

Free real-time operating system for embedded systems. Can run with 1.5 kB of RAM and 5 kB of ROM. Native ports are available for OS X and Linux.

Helical antenna for UHF (437 MHz).

spigot is a calculating program. It supports the usual arithmetic operations, square and cube roots, trigonometric and exponential functions, and a few other special functions such as erf.

spigot differs from the average calculating program in that it is an exact real calculator. This means that it does not suffer from rounding errors; in principle, it can keep generating more and more digits of the number you asked for until it runs out of memory.

In particular, if you ask for a complex expression such as sin(sqrt(pi)), then most calculating systems would compute first pi, then sqrt(pi) and finally sin(sqrt(pi)), accumulating a rounding error at each step, so that the final result had a build-up of error and you would have to do some additional error analysis to decide how much of the output you could trust.

spigot, on the other hand, does not output any digit until it is sure that digit is correct, so if you ask for (say) 100 digits of sin(sqrt(pi)) then you can be sure they are the right 100 digits.

How to choose and configure keyboards for efficient typing. Found Wed Dec 21 18:38:57 2016, rediscovered Tue Aug 28 01:08:05 2018.
The blog has other interesting articles, e.g. https://stevelosh.com/blog/2018/08/a-road-to-common-lisp/, https://stevelosh.com/blog/2013/09/teach-dont-tell/