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.

Overview of calendar and scheduling software for Linux.

Mudballs was written with the goal of providing an easy to use system for loading1 Common Lisp code into your image in a reliable and predictable manner. If you are new to Common Lisp, think of it as the start of a CL equivalent to Perls CPAN or Ruby's RubyGem's.

Intriguing collection of examples demonstrating pictures created using PGF and TikZ tools.

Tools for processing of GPS track data.

Smith chart tool which runs in a Javascript-capable browser. The site also has tools for astronomical calculations, sun dials, etc. (in German)

FPGA programming in C.