For more information, check out the release notes.
Note: DD4T 2.5 is only available for Microsoft.NET. The latest version of DD4T for Java is 2.1.5. For more information, see releases.
DD4T (Dynamic Delivery for Tridion) enables the use of MVC frameworks in Java and .NET with Tridion. At its core, DD4T publishes Pages and Components as data into your Content Data Store rather than as code to your filesystem. You can then leverage tools which you know; such as ASP.NET MVC, Spring - or anything that can use REST to deliver your content in any view you like.
DD4T is built by the community. So, we depend on people's own time to help develop new features and fix bugs. You can help too!