QueryFS is a FUSE-based virtual filesystem that is based on queries. There are plugins to parse various query syntaxes and each query creates a virtual directory. Currently the most elaborate query language is SQL-based; you can either provide access to data stored in an SQL database, or keep an index of files in the SQL database and generate search directories with symlinks to found files. QueryFS and its SQL2 query DSL fully support creation of refinable searches: for example, the author has an index of downloaded email files; one can see all the distinct senders registered in the DB and then go into a directory of one sender and see all accounts that ever received an email from this sender.
Verish is a language for reasoning that resembles a natural language. It is equivalent to Lower Predicate Calculus, and has a built-in framework for defining and using abbreviations, and for introducing additional principles of reasoning that can be automatically expanded into a sequence of steps that use only basic principles of reasoning. It has a basic reasoning checking function, and can automatically expand one additional principle of reasoning into a sequence of steps using only the basic principles. It can also add HTML markup to a proof for display as a Web page.
RoseThorn is a cross-platform library for 2D and 3D games running on GNU/Linux (and possibly other Unix-like OSes) and Windows. Features include: hardware accelerated 2D and 3D rendering; Ogg and WAV Sound support with OpenAL; Lua scripting; BMP, JPEG, and PNG image loading and saving (from screenshots); easily created and modified user interfaces with XML and CSS, combined with Lua event handling; separate 2D and 3D libraries; support for multiple fonts in both TTF and bitmap formats; support for OBJ, 3DS, MD5, and RTM model formats; skeletal animation (a work in progress); support for UDP and TCP networking; thread and mutex support; a Simple Shader API; 2D animated sprites; and some basic cryptography support. There is simple event management, with key/mouse bindings easily customized from the in-game console, config file, command line, or GUI.
Galois is a computer game of the "falling blocks" type, but with unique features. Unlike most other games of that type, it is not limited to blocks made of four two-dimensional, square bricks: you can choose among several different brick shapes, blocks composed of more or fewer bricks, and even between two- and three-dimensional games.
Upmf is a source-based package manager written almost completely in Scheme. The user is able to search, build, and remove packages. Since Scheme through GUILE is very extensible, the user can customize the procedures, or even exchange them with his own, if wanted. Packages are stored in their own self-contained directories and are incorporated into the filesystem with help of GNU Stow.
xllmnrd is an IPv6 LLMNR responder daemon (primarily for GNU/Linux operating systems). It allows Microsoft Windows clients to get the IPv6 address of a server on the same local network without any DNS configuration and effectively complements IPv4-only NetBIOS name resolution provided by Samba.
pyHIDS is a host-based intrusion detection system. It uses an RSA signature to check the integrity of its database. Alerts are written in the logs of the system, and can be sent via email to a list of users or on IRC channels (through the irker IRC client). You can define rules to specify files to be checked periodically.
OpenConnect server (ocserv) is an SSL VPN GNU/Linux server. Its purpose is to be a secure, small, fast, and configurable VPN server which depends on standard protocols like TLS 1.2 and Datagram TLS. It implements the AnyConnect SSL VPN protocol and is compatible with the OpenConnect VPN client (compatibility with other Anyconnect SSL VPN clients is experimental).