0 A.D. (pronounced "zero ey-dee") is a cross-platform real-time strategy (RTS) game of ancient warfare. It's a historically-based war/economy game that allows players to relive or rewrite the history of ancient civilizations, each depicted at their peak of economic growth and military prowess.
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.
4Suite XML is a Python-based toolkit for XML application development. It features a library of integrated tools for XML processing, implementing open technologies such as DOM, SAX, XPath, XSLT, XInclude, XPointer, XLink, XUpdate, RELAX NG, and XML/SGML Catalogs. The RDF and Repository components of 4Suite are separate packages that must be installed separately, on top of 4Suite XML.