This page outlines some of contributors that contributed to Jackson 2.12: it is not an exhaustive list but summarizes some of larger features. List is no almost certainly incomplete (apologies to anyone whose contribution is accidentally left out) as well as subjective -- no feature is insignificant, and omission from here (intentional or accidental) is not meant as value judgment.

Special thank you notes to following module maintainers (existing and new) for their contributions (in alphabetic module order):

• Blackbird (NEW in 2.12!): Steven Schlansker (@stevenschlansker) contributed a replacement module for Afterburner called Blackbird (clever name, even!)
  • Designed module specifically work better with newer (past-Java 8) JVMs, like JVM 11 and JVM 14
• Java 8 date/time: Michael O'Keeffe (kupci@github)
  • Helped unify Date/Time handling significantly for 2.12 by fixing issues, reviewing PRs.
• Kotlin: Drew Stephens (@dinomite) and Vyacheslav Artemyev (@viartemev)
  • Further improved Kotlin module to use new extension points introduced by core databind module
• Scala: PJ Fanning (@pjfanning)
  • Fixed many long-standing issues with Scala module to "catch up" with core databind
  • Has handled release responsibilities for the module since previous maintainers moved on

Jackson 2.12 significantly improves metadata included with modules, to support more advanced dependency management. Special thank you to following contributors:

• Jendrik Johannes (@jjohannes): contributed Gradle Module Metadata improvements (like databind#2726)
  • Can significantly improve dependency version handling with Gradle 6, see this blog post
• Marc Magon (@GedMarc): contributed further improvements to Java Module System (JPMS) metadata (module-info.class) regarding dependencies to JavaEE dependencies (JAXB, JAX-WS)

Jackson 2.12 contains support for many highly-requested features (now tagged with most-wanted label); things that users have waited for years in some cases (and less in others :) ). Here are the Most Wanted features, from oldest to newest:

• Marc Carter (@drekbour) provided the PR for the VERY OLDEST open feature request
  • Impressively simple solution to complicated problem, solution for which had evaded us for a... while. :)
  • See databind#43 for details

• Baptiste Pernet (@sp4ce) provided the PR for this long-time favorite feature request by users -- basically reverse of @JsonIgnoreProperties (opt-in vs opt-out)
  • See databind#1296 for details

• Lovro Pandžić (@lpandzic) helped get this perennial favorite feature request to finally be implemented in 2.12 (after many close misses)
  • See databind#1498 for details

• Gunnar Morling (@gunnarmorling) and Youri Bonnaffé (@youribonnaffe)
  • Provided initial PR for support, tests, and guidance on improvements.
  • See databind#2709 for details

• Carter Kozak (@carterkozak) for important fixes to Static Factory generic type coercion (for example, databind#2895), related areas
  • Particularly helpful was testing during Release Candidates, including integration tests