Polymer vs Symfony: What are the differences?
Developers describe Polymer as "A new library built on top of Web Components, designed to leverage the evolving web platform on modern browsers". Polymer is a new type of library for the web, designed to leverage the existing browser infrastructure to provide the encapsulation and extendability currently only available in JS libraries. Polymer is based on a set of future technologies, including Shadow DOM, Custom Elements and Model Driven Views. Currently these technologies are implemented as polyfills or shims, but as browsers adopt these features natively, the platform code that drives Polymer evacipates, leaving only the value-adds. On the other hand, Symfony is detailed as "A PHP full-stack web framework". Symfony is written with speed and flexibility in mind. It allows developers to build better and easy to maintain websites with PHP. Symfony can be used to develop all kind of websites, from your personal blog to high traffic ones like Dailymotion or Yahoo! Answers.
Polymer belongs to "Front-End Frameworks" category of the tech stack, while Symfony can be primarily classified under "Frameworks (Full Stack)".
"Web components" is the top reason why over 48 developers like Polymer, while over 153 developers mention "Open source" as the leading cause for choosing Symfony.
Polymer and Symfony are both open source tools. It seems that Polymer with 21.1K GitHub stars and 2K forks on GitHub has more adoption than Symfony with 21K GitHub stars and 6.98K GitHub forks.
eTobb, Improvely, and Chooos are some of the popular companies that use Symfony, whereas Polymer is used by AX Semantics, USERcycle, and Telemetry. Symfony has a broader approval, being mentioned in 355 company stacks & 267 developers stacks; compared to Polymer, which is listed in 41 company stacks and 30 developer stacks.