Vue 2.0 launched on the September 30, 2016. Check out this post of Evan You at https://medium.com/the-vue-point/vue-2-0-is-here-ef1f26acf4b8#.ifpgtjlek .
Across this book, we used the newest version; however, I tried to reference the way of doing things in the first generation of Vue whenever it was necessary. Actually, the API is almost the same; there are some slight changes, some deprecated attributes, but the whole interface provided to the final user remains almost untouched.
Nevertheless, it was almost rewritten from scratch! Of course, there are some parts of code that were almost 100% reused, but overall, it was a major refactor and some of the concepts were completely changed. For example, the rendering layer was completely rewritten. If, earlier, the rendering engine was using the real DOM, now it uses a lightweight virtual DOM structure ( https://github.com/snabbdom/snabbdom ). Its performance beats everything! Check out the benchmark figure in the following:
Performance...