ttmkfdir is a tool to create valid and complete fonts.dir files from TrueType fonts. It is very useful when you plan to use a TrueType enabled font server that is based on the X11R6 sample implementation (xfsft for instance). Great care has been taken to correctly identify the encodings that a given TrueType font supports.
Twisted is an event-based framework for Internet applications. It includes a Web server, an SMTP/POP3 server, a telnet server, an SSH server, an IRC server, a DNS server, a generic client/server pair for remote object access (Perspective Broker), and APIs for creating new protocols. It supports integration with GTK+, GTK+ 2, Qt, Tkinter, wxPython, Mac OS X (PyObjC) and Win32 event loops. It also supports TCP, SSL and TLS, UDP, Unix sockets, multicast, and serial ports. Supported protocols include HTTP, FTP, SMTP, POP3, IMAP, TOC, OSCAR (AIM and ICQ), SSH, DNS, IRC, NNTP, Jabber, SOCKSv4, Telnet, SIP (for VoIP), and XML-RPC and SOAP using external packages. Most protocols are supported as both servers and clients.
The Virtual Tab Window Manager (VTWM) is a virtual window manager with adjustable graphical complexity. With minimal settings, it is ideal for limited resource situations, using little memory, little CPU time, few colors, and little bandwidth. Fully blown, it supports m4 and regex processing of the resource file, sound effects, user-defined color icons and buttons, and more.
WideStudio is a multi-platform integrated development environment for building windowed event-driven applications. It uses its own independent class libraries. Automatic source code generation is provided by the application builder, which also provides project management and automatic makefile generation. WideStudio can be used to develop applications on Linux, Solaris, and Windows.
X11, or X, is a vendor-neutral, system-architecture neutral network-transparent window system and user interface standard. In other words, it's a GUI for UNIX. X can use your network -- you may run CPU-intensive programs on high powered workstations and display the user interface (the windows) on inexpensive desktop machines.