Client-side web application frameworks, such as Knockout, Backbone, and Ember, existed before AngularJS was released in 2012, but AngularJS was the first to gain widespread adoption and has retained the title of "Most popular front-end framework" for many years. However, because it was the first, there were many rough edges that developers soon found annoying. According to the State of JavaScript 2017 survey, out of all those who have used AngularJS (version 1), only 32.9% would use it again.

Therefore, when React was released in 2013, many Angular developers migrated to React, boosting React's popularity. Satisfaction among React developers is also high, with 93.1% of developers in the aforementioned survey saying they would use it again.

In 2014, the AngularJS team attempted to respond by promising to completely re-write the AngularJS framework. However, the new version (now called "Angular") would be incompatible with the old version (now called "AngularJS"), which means migration from AngularJS to Angular would require a complete rewrite of the application. This caused much backlash in the Angular community, further pushing more developers toward React. To add to the woes of Angular, there were many delays in the development of Angular 2, and the final version was released only 2 years later, in 2016. Two years is a very long period of time in the front-end ecosystem, and by then, React had already captured the lion's share of developers.

Vue.js is the newest kid on the block, and is designed with the lessons learned from both Angular and React (Vue.js's creator, Evan You, was an architect at Google). Since its release in 2014, it has, in a way, made the same impact on the ecosystem as when React first came out. It also has a high satisfaction rate, with 91.1% of developers saying they would use Vue.js again.

In terms of hard numbers, according to the same State of JavaScript survey, out of 23,704 respondents, 14,689 (62.0%) have used React, a slight gain from 57.1% in 2016. A total of 11,322 (47.8%) have used AngularJS 1, down from 63.6% in 2016, and 6,738 (28.4%) have used Angular 2, up from 20.5% in 2016. The biggest climber has been Vue.js, with 5,101 (21.5%) of respondents saying they've used it, almost doubling the figure from 10.8% in 2016.

In terms of contributors to the source code, 1,598 developers have contributed to Angular, 1,177 have contributed to React, and only 187 have contributed to Vue.js.

It's important to note that the most popular framework doesn't mean it is the best framework, and a developer should never choose a framework solely based on its popularity (a.k.a. hype-driven development). However, the more popular a framework is, the more developers use that framework, and thus there is likely to be more community support on forums and Q&A sites, such as Stack Overflow. From the business' perspective, it'll also make it easier to hire developers.

Therefore, from the popularity/community/ecosystem point of view, Angular is in decline, Vue.js is on the rise, but React is still the obvious choice.