baresip is a bare-bones SIP user agent. It supports SIP, SDP, RTP/RTCP, and STUN/TURN/ICE, and IPv4 and IPv6, and is RFC-compliant and has portable C89 and C99 source code. A modular plugin architecture provides stdio, cons, and evdev user interfaces, celt, g711, g722, gsm, ilbc, l16, and speex audio codecs, alsa, coreaudio, gst, portaudio, oss, winwav, and mda audio drivers, speex_pp, speex_aec, speex_resamp, and sndfile audio filters, the avcodec video codec, avformat, quicktime, qtcapture, v4l, and v4l2 video sources, sdl, opengl, and x11 video display drivers, and srtp media encoding.
restund is a modular STUN/TURN server that is designed around the principle of a lightweight core and server modules that extend its functionality. Both UDP and TCP are supported, along with IPv6 and IPv4. Supported modules include STUN, TURN, MySQL database, syslog, and status monitoring.
TikZ-dependency allows you to draw dependency graphs in LaTeX documents with little or no effort. The package has a very easy to learn, high level interface that can be used to draw simple dependency trees, complex non projective graphs, bubble parses, and in general any kind of graph that is based on a sequence of nodes and edges among these. It is based on PGF/TikZ and can be used either with latex or pdflatex. It comes with very comprehensive documentation that will get you started in 10 minutes, even without any prior knowledge of TikZ. It also provides a lot of styling facilities to let you personalize the look and feel of the graphs.
Serv-U is a powerful and easy-to-use file server which supports the FTP, HTTP, and SFTP (via SSH2) protocols to ensure maximum compatibility with the widest range of transfer client software. It supports SSL encryption, provides a Web-based interface to allow administrators to remotely access and configure the file server, includes a built-in transfer client to allow users to upload and download files from their Web browsers, provides photo sharing capabilities, integrates with Active Directory (providing levels of security based on Organizational Units), and can be accessed and administered in 13 different languages simply by choosing an appropriate language upon login.