Version 6 of Node.js is four times faster than Node.js v4, which is the latest deployment release line. "Imports [of code modules] and startup time [are] dramatically faster than it used to be," Node.js Foundation Community Manager Mikeal Rogers said. The process for finding files has been streamlined, said James Snell, a member of the Node core team.
The latest version also features Google's V8 5.0 JavaScript engine, which improves support for the ECMAScript 2015 (ES6) specification underlying JavaScript. "In general, we've gone from [complying with] about 58 percent of ES6 to about 93 percent of ES6," Rogers said. New capabilities include default function parameters and REST parameters, for more easily expressing what a function is supposed to do. "These are the kinds of features that languages like Python have had for a long time," he said.
For security, a Buffer API in version 6 will reduce the risk of bugs and vulnerabilities finding their way into applications, via a constructor method for building buffer instances. The zero-fill-buffers command flag, meanwhile, lets developers use older modules that have not been updated to use this API. Also, V8's math.random implementation for generating random numbers is more secure, and it's now easier to work with file systems that use multiple character encodings, such as Linux.
Version 6 becomes the Current release line, turning into the LTS (Long Term Support) release this fall. Version 5 will be maintained for a few more months, and version 4, the current LTS release, goes to maintenance mode in a year, with only critical bugs, security fixes, and documentation updates permitted. The Foundation advises users to transition from v4 to v6 in October, when v6 becomes the LTS release.