Apple mimics other browser makers, produces Safari developer preview
Labeled "Safari Technology Preview," the browser can be downloaded by anyone, not just Apple registered developers, and runs alongside the production-quality Safari on OS X. The preview will be updated via the Mac App Store every two weeks.
The Safari preview, Apple said, is a "more convenient and stable way" to run a developer-grade build than WebKit's nightly iterations. WebKit is the open-source project that feeds code to Safari, and like other browser "channels" -- such as Google's Chrome Canary or Mozilla's Firefox Nightly -- features daily updates.
Safari Technology Preview has a major advantage over WebKit's nightlies in that the former is signed by Apple. The means it supports iCloud, which Safari uses to synchronize bookmarks and opened tabs, making it easier to bounce between preview and production versions on one or more Apple devices.
Developers also get the latest additions to Web Inspector, Apple's tool for prototyping and debugging websites, in the preview.
Among the newest WebKit features in the initial preview were a faster JavaScript compiler and support for Content Security Policy Level 2, which protects Web apps from content injection vulnerabilities leveraged by cross-site scripting (XSS) attacks.
The preview can be downloaded from Apple's developer website. OS X El Capitan 10.11.4 or later is required. More information about the sneak peek was published on the WebKit blog.