I've been an amateur programmer for a few years. I started programming back in the '80s with a TRS-80 Model I and a C64 and have used various systems over the years including multiple versions of DOS, Windows, OS X, Linux and other versions of *NIX including Solaris, NetBSD and FreeBSD.
I'm partial to programming for the command line, though I've done a small amount of CGI. My languages of choice are C and Bash; however, I've used BASIC, Pascal, Perl, C++ and ForTran as well.
The downloads I listed below are cross platform and I have successfully compiled them on various versions of *NIX. Some may require you to use GNU make which appears to be installed as gmake on the BSDs.
Biorhythm is a highly customized port of a BASIC program for the TRS-80.
MagicSquare was a game available on Merlin. My port is playable using the numeric keypad. On my freeshell site I also have a javascript version available playable with the mouse in a browser.
Mean is a simple statistics tool for the command line. If all you need is sum, product, range, arithmetic and geometric means for double precision it should work.
Roll is modelled after the utility available on TELEHACK and simulates throwing up to ten dice.