Vabotu - More than slack. More than Trello. FREE.
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
Do - Do helps you run productive meetings. Do work you love.
RenPy - Ren'Py is a free and cross-platform visual novel engine that helps you use words, pictures, and...
Kurator - The premier Chrome extension for savvy researchers and publishers alike. Curate your interest and publish to your website, newsletter and social media sites directly from the browser.
Quest - Quest lets you create sophisticated text-based games, without having to program.