Here are people who have contributed to development Jackson JSON processor
Base modules
(version numbers in brackets indicate release in which the problem was fixed)
(NOTE: incomplete -- need to collect info from sub-projects, pre-2.9)

Tatu Saloranta, tatu.saloranta@iki.fi: author

Vojtěch Habarta (vojtechhabarta@gitub)

* Reported [JAXB#32]: Fix introspector chaining in `JaxbAnnotationIntrospector.hasRequiredMarker()`
 (2.9.3)

Tuomas Kiviaho (TuomasKiviaho@github)

* Reported #42: NPE from MrBean when `get()` or `set()` is though as property
 (2.9.5)

Alexander Onnikov (aonnikov@github)

* Reported #44: (jaxb) `@XmlElements` does not work with `@XmlAccessorType(XmlAccessType.NONE)`
 (2.9.6)

William Headrick (headw01@github)

* Reported 54: Afterburner` SuperSonicBeanDeserializer` does not handle JSON Object
  valued Object Ids (like json)
 (2.9.7)

Jeffrey Bagdis (jbagdis@github)

* Reported, contributed fix to #49: Afterburner `MyClassLoader#loadAndResolve()`
  is not idempotent when `tryToUseParent` is true
 (2.9.9)

Dan Sănduleac (dansanduleac@github)
 
* Reported, contributed fix for #69: `ALLOW_COERCION_OF_SCALARS` ignored deserializing scalars
   with Afterburner
 (2.9.9)

Georg Schmidt-Dumont (georgschmidtdumont@github)

* Reported #74: MrBean module should not materialize `java.io.Serializable`
 (2.9.9)

Jeffrey Bagdis (jbagdis@github)

* Reported, contributed fix for #49: Afterburner `MyClassLoader#loadAndResolve()`
  is not idempotent when `tryToUseParent` is true
 (2.9.9)

Harrison Houghton (hrhino@github)

* Suggested, contributed impl for #52: Interfaces may have non-abstract methods (since java8)
 (2.10.0)

Bartosz Baranowski (baranowb@github)

* Reported #84: (jaxb) Add expand entity protection and secure processing to
  DomElementJsonDeserializer
 (2.10.0)


Robby Morgan (robbytx@github)

* Contributed #109: (mrbean) Fix detection of inherited default method in Java 8+ interface
 (2.11.3)
* Contributed #110: (mrbean) Avoid generating implementations of synthetic bridge methods
 (2.11.3)