Sanewall is a firewall builder for Linux that uses an elegant language abstracted to just the right level. This makes it powerful and easy to use, audit, and understand. It allows you to create very readable configurations even for complex stateful firewalls. Sanewall can be used for almost any purpose, including control of any number of internal/external/virtual interfaces, control of any combination of routed traffic, setting up DMZ routers and servers, all kinds of NAT, providing strong protection (flooding, spoofing, etc.), transparent caches, source MAC verification, blacklists, and whitelists. Newer versions abstract the differences between IPv4 and IPv6, allowing you to define a common set of rules for both, while permitting specific rules for each as you need. Sanewall is a fork of FireHOL and can make use of existing FireHOL configurations.
OpenReviewScript is software for creating review Web sites. All you need is PHP hosting with a database. The simple installer gets you set up in minutes. A theme system lets you create or modify designs without needing to know any PHP. All themes are CSS/HTML based with a separate set of template files that control the content on each page. You have access to every single line of code; nothing is encrypted.
sVimPy is a very small Python virtual machine intended for use in microcontroller projects. At the moment, it supports about 3/4 of all opcodes used in python3k. Most data types are supported. The intended goal is to use this VM in environments like Atmel's ATmega chips (2-8kb RAM). The microcontroller bootloader is still missing (no arduinos left for experimentation). Classes are not supported. Features include: function calling, a stack based VM, garbage collection, very low memory usage, an interactive debugging console, dictionaries and tuples, iterations, VM single stepping (game loop usage is possible), C function calling, a small memory footprint, fast performance, the ability to be used as a library in other projects, a simple API + code, possible usage as a small deployment executable for Python projects.