Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
EncFS is an encrypted pass-through filesystem which runs in userspace on Linux (using the FUSE kernel module). Similar in design to CFS and other pass-through filesystems, all data is encrypted and stored in the underlying filesystem. Unlike loopback filesystems, there is no predetermined or pre-allocated filesystem size.
Evolvotron is an interactive "generative art" application to evolve images/textures/patterns through an iterative process of random mutation and user-selection driven evolution. If you like lava lamps, and never got tired of the Mandelbrot set, this could be the software for you. It's implemented using Qt, and is multithreaded.
ZXTune is a set of portable cross-platform applications (GUI/CLI) intended to play chiptunes originally created for ZX Spectrum. It features advanced ripping possibilities that let you search for music in big data sets. Supported playback formats include AY, AS0, ASC, FTC, GTR, PSC, PSG, PSM, PT1, PT2, PT3, SQT, ST1, ST3, STC, STP, TXT, TurboSound, VTX, YM, CHI, DMM, DST, PDT, SQD, STR, TFC, TFD, and COP. Supported compressed formats include CHARPRES, CC3, CC4, CC4PLUS, DSQ, ESV, GAM, GAMPLUS, HRUM, HRUST1, HRUST2, LZH1, LZH2, LZS, MSP, PACK2, PCD61, PCD62, TLZ, TLZP, TRUSH. Supported archived/container formats include FDI, HOBETA, HRIP, LHA, RAW, SCL, TD0, TRD, ZXZIP, ZIP, RAR, SNA128, and Z80.
ChaiScript is an embedded scripting language designed from the ground up to directly target C++ and take advantage of modern C++ development techniques. Being a native C++ application, it has some advantages over existing embedded scripting languages. It uses a header-only approach, which makes it easy to integrate with existing projects. It maintains type safety between your C++ application and user scripts. It supports a variety of C++ techniques including callbacks, overloaded functions, class methods, and STL containers.
Galera wsrep provider is a dlopenable generic replication library which implements the wsrep provider API. It provides very efficient synchronous replication, and multi-master and "parallel applying" capabilities for opaque data buffers. Its primary focus is data consistency. A transaction is either applied on every node, or not at all. It works anywhere TCP works, including on WAN, and can utilize UDP multicast where available. It is used by the MySQL-wsrep patch project to create true multi-master MySQL/InnoDB clusters.
peekabot is a versatile 3D visualization tool targeted at robotics researchers and developers. It's multi-platform, general purpose, easily extendable, scalable, and does not depend on any other frameworks to function. It also provides some functionality for interacting with your robots using the GUI. You can test your algorithms in both simulated and real environments. The only requirement is that the device can use TCP/IP.
Arx Libertatis is a cross-platform, open source port of Arx Fatalis, a 2002 first-person role-playing game developed by Arkane Studios. Arx Fatalis features crafting, melee and ranged combat, and a unique casting system where the player draws runes in real time to effect the desired spell. The Arx Libertatis source code is based on the publicly released Arx Fatalis sources. This does however not include the game data, so you need to obtain a copy of the original Arx Fatalis or its demo.