HttpCore 4.0 is considered stable and ready for use in production. We are working in incremental improvements and performance optimizations for 4.1 release.
The HttpCore forms the foundation of HttpClient 4.0 and can also be used separately to build custom client- and server-side HTTP services.
The redesign of HttpClient is now complete. All known architectural deficiencies and problems of the old architecture have been resolved. HttpClient now sports a cleaner, more flexible and expressive API, a more modular structure, improved performance and reduced memory footprint.
HttpClient 4.0 is now feature-complete and its API has been frozen. All official releases in the 4.0.x code line are expected to be API compatible.
The 3.1 branch of Commons HttpClient is now nearing its end of life. Major bugs will still be fixed, but no new features added. No more public releases are expected.