tSIP is a Windows-only SIP softphone application built on top of the baresip SIP user agent framework, which itself relies on the re (libre) and rem (librem) networking and media libraries. The repository bundles a large number of third-party libraries as source code: Opus, Speex, G.722, GSM, FFmpeg, OpenSSL, WebRTC audio processing, ZRTP (GNU ZRTP), PortAudio, SDL2, Scintilla, Lua, and JSONcpp. The tSIP GUI is written in Borland C++ Builder VCL, with forms for call management, contacts, history, programmable buttons, hotkeys, Lua scripting, and configuration. The architecture is a classic Windows desktop application with a modular plugin system for codecs and media sources. The codebase is a snapshot from around 2012-2015, with many outdated libraries and compiler-specific code, making it high-risk for reuse without significant modernization. It is not a data research project; it is a full-featured VoIP client.