The philosophy of versions

Description

In 2015, the PHP project released version 7.0 of the PHP language. Doing so was the culmination of several years of discussion and hard work to resolve what a new major version would look like, what would be included, and most importantly, what would be broken for existing users. In the end, PHP 7 was released with almost no backward compatibility breaks for well-written, modern PHP 5 code. As a result, uptake of PHP 7 after three years has been—depending on which source you use and how you measure it—between 33% and 67%.

Adam Harvey explores the PHP project’s significant advantage: other languages had been through the same thing before. By reference to peers—Python, Perl, C++—developers were able to learn from their experiences. And since then, the process has only continued as languages such as Rust, Go, and JavaScript go through similar transitions. He walks you through the insights gleaned from the PHP 7 process and explains how other projects—whether languages or libraries—can better handle their road maps, backward and forward compatibility stories, and ultimately, their versions.