Commandline Challenge - Test your command line skills

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

Prompt - Prompt provides fully-integrated writing education solutions, combining instruction, curriculum, and feedback. We support educational institutions, companies, and individuals.

Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.

Cwiki - A Command line interface for searching Wikipedia!

Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.