Easle - Discover and hire hand-picked independent artists
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
UnitedMasters - Creator tools for artists to get smart, get fans, get paid
Ink by Inkle - ink is a popular open source scripting language for branching stories, designed for writers
Upwork - Forget the old rules. You can have the best people. Right now. Right here.
Quest - Quest lets you create sophisticated text-based games, without having to program.