Oracle JET is an open source toolkit developed by Oracle which can be leveraged to build enterprise applications in JavaScript. It's important to identify that Oracle JET is not a framework, only a toolkit. ...But, what does that mean? well, you can't just swap out Angular or React (or the many other JS Frameworks) for Oracle JET! Instead, application developers can pick and choose thoroughly tested, modular components from the toolkit (cookbook!) that leverage JQuery and KnockoutJS and weave them into their application development - code snippets, if you like. Recent versions of JavaScript, HTML5 and CSS3 architecture principles are quickly established.