The new release delivers significant changes to the language, compiler and tools. These span from highly requested new language features like generics, to a new compiler infrastructure that lays the foundation for TypeScript tools scalability, to hundreds of bug fixes and general improvements, said Jonathan Turner, a program manager with the TypeScript team at Microsoft, in a blog post.
And with the 0.9 release, "along with important new language features and improved tooling capabilities in Visual Studio, we've done considerable work to scale the TypeScript language service for large application development, giving developers a smooth, interactive experience regardless of project size," Somasegar said.
The introduction of generics to the language—the most-requested feature—improves developer efficiency. "Generics take advantage of the strong type inference that TypeScript already provides, allowing users to have better static error reporting and richer tooling, in many cases without any additional type annotations," Turner said.
In addition, the TypeScript compiler has been re-engineered, laying the foundation for great tooling scalability going forward, and provides a much higher-fidelity implementation of the TypeScript language specification, Turner said.
"The new compiler addresses over 150 issues reported on CodePlex since the 0.8 release. These include places where the compiler now catches potential errors more reliably, more accurate tools and general improvements across the board," Turner said. The new compiler has been designed to enable better incremental performance while editing code in integrated development environments (IDEs), he added.
Meanwhile, Somasegar noted that TypeScript has already been positively impacting Web development.
Moreover, the TypeScript ecosystem continues to grow. Hundreds of developers are engaging with the project and more than a dozen editors now support TypeScript, enabling development with TypeScript in a variety of popular tools and across multiple major platforms, Somasegar said. TypeScript also won a 2012 Open-Source Rookie of the Year award.