Support for Java Servlet 3.1, JavaServer Pages 2.3, Java Unified Expression Language 3.0 and Java WebSocket 1.0.
The default connector implementation is now the Java non-blocking implementation (NIO) for both HTTP and AJP.
A new resources implementation that replaces Aliases, VirtualLoader, VirtualDirContext, JAR resources and external repositories with a single, consistent approach for configuring additional web application resources. The new resources implementation can also be used to implement overlays (using a master WAR as the basis for multiple web applications that each have their own customizations).