C/C++: - Desktop App: Qt, wxWidget, Window Template Library (WTL) - Microsoft technologies: MFC, WTL, ATL, OLE, IE engine - Boost library: asio, regex, thread-pool, Signals, program options... - Third party libraries: zlib (compression/decompression), Axis2C (web services), libcurl (http/https) - PostgreSQL, MySQL C++ library, or ODBC C++ library, MongoDB (R&D) - Networking programming: epoll, socket, Mail protocols (POP3, IMAP, SMTP) - C++ standard library: STL, TR1 - Built-in framework or POCO framework with different features: event/signal-driven, xml/text configuration loading, thread-pool, pluginable...