When, Evan You, Vue.js creator ( http://evanyou.me/ ), was working at Google Creative Labs on one of the projects, they needed to fast prototype a rather big UI interface. Writing a lot of repeated HTML was clearly time- and resource-consuming, and that's why Evan started looking for some already existing tool for this purpose. To his surprise, he discovered that there was no tool, library, or framework that could fit exactly into the purpose of rapid prototyping! At that time, Angular was widely used, React.js was just starting, and frameworks such as Backbone.js were used for large-scale applications with MVC architecture. For the kind of project that needed something really flexible and lightweight just for quick UI prototyping, neither of these complex frameworks were adequate.
When you realize that something cool does not exist and you are able to create it—just do it!
Note
Vue.js was born as a tool for rapid prototyping. Now it can be used to build complex scalable reactive web applications.
That was what Evan did. That is how he came to the idea of creating a library that would help in rapid prototyping by offering an easy and flexible way of reactive data binding and reusable components.
Like every good library, Vue.js has been growing and evolving, thus providing more features than it was promising from the beginning. Currently, it provides an easy way of attaching and creating plugins, writing and using mixins, and overall adding custom behavior. Vue can be used in such a flexible way and is so nonopinionated of the application structuring that it definitely can be considered as a framework capable of supporting the end-to-end building of complex web applications.