Yesterday marked the beginning of Apple’s annual Worldwide Developer Conference, or WWDC for short. Along with new versions of their iOS and OS X operating systems, they announced that they would be open sourcing their Swift programming language, including support for Linux. This drew by far the largest cheers of the day from the 5,000 or so developers who had assembled in Moscone West for the kickoff keynote. While Apple doesn’t have a perfect track record when it comes to following through on open source promises, it has been better lately. And there are a few good reasons that developers are so excited about the proposition of Swift being open sourced.

On today’s web, server applications are typically written in an interpreted language like Javascript, Ruby, or PHP, or a managed language like C# or Java. Swift is different than these languages — it is a compiled language, which gives it significant speed and scaling advantages compared to the languages listed above. And it gains these advantages while still offering all of the high-level conveniences we expect in our programming languages today.

One of the core design philosophies of Swift is safety. Inferred types allow for less error prone code. Memory is managed automatically. Variables are always initialized before use, arrays and integers are checked for overflow. Errors are bounded and can’t throw exceptions, preventing crashes. All of these safety features add up to one thing — increased reliability. And when you are hosting a web service, increased reliability pays dividends in the most important currency on the web — uptime.

With the backing of the world’s largest and most influential technology company, it’s not hard to imagine a strong and vibrant ecosystem springing up around Swift as a server-side programming language once it has been open sourced. It has already seen tremendous adoption within the iOS and OS X community, despite it’s rough edges, and is continuing to grow in popularity. And with the Swift team’s relentless optimizations, it’s getting faster with every release.

Imagine lightning-fast, scalable deployments of RESTFUL web services, or a Rails-like front-end framework written in Swift — native, fast, and safe. Quicker responses, and lower server costs, without an increase in complexity.

The future of Swift seems to be very bright indeed.