]> 3.1.0-Final A number of API classes in Resteasy 2, which is based on the JAX-RS 1.1 specification (https://jcp.org/en/jsr/detail?id=311), have been deprecated in, and eventually removed from, Resteasy 3, which is based on JAX-RS 2.0 (https://jcp.org/aboutJava/communityprocess/final/jsr339/index.html). In particular, those classes are deprecated by the end of the 3.0.x series of releases, and removed as of the 3.1.0.Final release. For the most part, these changes are due to the fact that a number of facilities specific to Resteasy were introduced in Resteasy 2 and then formalized, in somewhat different form, in JAX-RS 2.0. A few other facilities in Resteasy simply were not carried over to Resteasy 3. This short document describes the principal changes from Resteasy 2 to Resteasy 3 and gives some hints about upgrading code from the Resteasy 2 API to Resteasy 3. Additional information can be found in the Resteasy Users Guides (http://resteasy.jboss.org/docs.html). A more extensive treatment may be found in the O'Reilly book RESTful Java with JAX-RS 2.0, 2nd Edition, by Bill Burke. &Client_Framework; &Interceptors; &Asynchronous; &Validation; &Cache; &Miscellaneous;