The goals of the Type Annotations Project were:
As of March 2014, development is finished and integration into JDK 8 is complete. The Project's mailing list (type-annotations-dev) and Mercurial forest (type-annotations) have been archived. The JSR 308 Expert Group mailing list (type-annotations-spec-experts) has also been archived.
Bugs in how javac handles type annotations are tracked in tools/javac.
Bugs in how Core Reflection exposes type annotations are tracked in core-libs/java.lang:reflect.
Bugs in how Annotation Processing exposes type annotations are tracked in core-libs/javax.lang.model.
The Project was sponsored by the Compiler Group.
The Java Tutorial: Type Annotations and Pluggable Type Systems
JavaOne 2013 presentation: Enhanced Metadata in Java SE 8
Type Annotations (JSR 308) and the Checker Framework at the University of Washington.