Another backup tool similar to Apple's TimeMachine for Linux. It appears to be based on git.

Scripting extension for Firefox. Used
<a>here</a> to make the appearance of pages more Plan9-like.

Look up a kanji drawn with the mouse.

Program to draw ASCII-Diagrams of electrical circuits.

List of free (as in freedom) readers for PDF files.

Web site offers a CAPTCHA test to distinguish between humans and robots. The results are used to correct texts from old books which were scanned.

Web calculator implemented in JavaScript. Implements arbitrary precision, plotting, prime testing, polynomial roots, matrix arithmetic and very limited (polynomials) symbolic integration. Written by Fabrice Bellard, who also wrote TinyCC, QEmacs, FFMPEG, QEMU and more: https://bellard.org/

Some software for dealing with Mac OSX metadata, including backup to a remote, non-OSX, unix machine.

rsnapshot is a filesystem snapshot utility for making backups of local and remote systems. Using rsync and hard links, it is possible to keep multiple, full backups instantly available. The disk space required is just a little more than the space of one full backup, plus incrementals. Depending on your configuration, it is quite possible to set up in just a few minutes. Files can be restored by the users who own them, without the root user getting involved. There are no tapes to change, so once it's set up, your backups can happen automatically untouched by human hands. And because rsnapshot only keeps a fixed (but configurable) number of snapshots, the amount of disk space used will not continuously grow. rsnapshot is written entirely in Perl.

Start of a series of blog articles about linkers.