QMentat helps you practice mental arithmetic. It uses arbitrary-length fixed point arithmetic, and can handle any size numbers, only limited by the size of your screen (and in the case of division with an integer result, the speed at which the number can be factored). It is also quite configurable, allowing you to tailor the questions to your needs.
4K Video Downloader is a video and audio downloader for YouTube, Vimeo, Facebook, Dailymotion, Metacafe, and other video-sharing services. It features video quality up to 4k resolution, FLV, MP4, and MKV support, extraction of audio to the MP3 format, and a "Smart Mode" for fast downloads.
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.
QSapecNG (Symbolic Analysis Program for Electric Circuits (New Generation)) is a Qt-based program for symbolic analysis of linear analog circuits. It consists of two independent parts, the SapecNG framework engine and the QSapecNG GUI. It was based on SapWin. Users can draw, solve, analyse, and manage analog circuits.
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, TF0/TFE, 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.
QuintoLabs Content Security is an ICAP server/URL rewriter that integrates with your Squid Proxy Server to provides rich content filtering functionality, sanitizing Internet traffic passing into internal enterprise networks. It may be used to block illegal or potentially malicious file downloads, remove annoying advertisements, prevent access to various categories of Web sites, and block resources with explicit content.
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.