xSiteable is a complete all-you-need package for creating sites that are fully relational, open source, fully templating-enabled, using only XML-based technologies to help you create complex sites on the fly. It packs such features as topic maps, notation for content, and the fast Sablotron xslt parser.
xbaydns provides a Web management interface for BIND 9. Its user-friendly Web interface is based on the Django framework. It has been tested on many OSes, including FreeBSD, Linux, and MacOS X Leopard. It provides an easy-to-use Web interface for DNS record management while implementing most of the advanced features provided by BIND.
xmltvdb creates a database from a set of xmltv listings and then provides a Web interface to view the TV listings in a grid format similar to many Web-based listings providers, but with user customization and no advertising. It supports explicit and bayesian classification of shows to highlight items you like and de-emphasize ones you don't.
yaSSL is a C++ based SSL library for embedded and RTOS environments, designed for individuals who prefer to use the C++ language. For a C-based solution, please see CyaSSL. yaSSL supports the industry standards up to TLS 1.2, and also includes an OpenSSL compatibility interface.
yaydl (yet another youtube downloader) is a commandline-oriented tool that allows you to download videos from video sharing Web sites (currently YouTube, Myvideo, Dailymotion, Clipfish, video.google, Metacafe, Sevenload, and Vimeo). The use of external programs like mplayer or ffmpeg enables it to re-encode the videos or to rip the audio off a video.