A cross-platform command-line utility that creates projects
Cookiecutter is a command-line utility to create projects from customizable and reusable templates. It helps bootstrap new projects with consistent structure, metadata, licensing, CI configs, and more—streamlining setup for a wide range of software projects.
ePen - A cross platform tool for creative writers and book authors. ePen is able to manage all information around a book project: The actual text, descriptions of the characters and scenes, the storyline.
socklib++ is a light-weight cross-platform C++ socket library. It provides both a high-level interface over iostreams if you want convenience, and a low-level interface if you just want portability.