GoJS is a JavaScript library for building interactive diagrams. It has a number of built-in features such as drag-and-drop, copy-and-paste, text editing, automatic layouts, templates, data binding and models, transactional state and undo management, extensible tools for custom operations, and more.
A thesaurus with unusual synonyms and historical quotes to give more inspiration to your writing. It is also quick to use: you can type out for example carefulwords.com/solitude to get synonyms.