Here are people who have contributed to the development of Jackson JSON processor
databind core component, version 2.x
(version numbers in brackets indicate release in which the problem was fixed)

(note: for older credits, check out release notes for 1.x versions)

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

Pascal Glinas:
  * Contributed fixes to 'MappingIterator' handling (Pull#58 and Pull#59)
   (2.1.0)
  * Reported #220: ContainerNode missing 'createNumber(BigInteger)'
   (2.2.2)

Joern Huxhorn: (huxi@github)
  * Suggested [JACKSON-636]: Add 'SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS' to allow
    forced sorting of Maps during serialization
   (2.0.0)
  * Reported #479: NPE on trying to deserialize a `String[]` that contains null
   (2.4.1)

James Roper:
 * Requested [JACKSON-732]: Allow 'AnnotationIntrospector.findContentDeserializer()'
    (and similar) to return instance, not just Class<?> for instance
  (2.0.0)
 * Suggested [JACKSON-800]: Adding a method for letting modules register
    DeserializationProblemHandlers
  (2.0.0)

Casey Lucas:
 * Reported [JACKSON-798]: Problem with external type id, creators
  (2.0.0)

Tammo van Lessen:
 * Reported [JACKSON-811]: Problems with @JsonIdentityInfo, abstract types
  (2.0.0)
 * Reported [JACKSON-814]: Parsing RFC822/RFC1123 dates failes on non-US locales
  (2.0.0)

Raymond Myers:
 * Suggested [JACKSON-810]: Deserialization Feature: Allow unknown Enum values via
    'DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL'
  (2.0.0)

Ryan Gardner:
 * Contributed #5 -- Add support for maps with java.util.Locale keys
    to the set of StdKeyDeserializers
  (2.0.1)

Razvan Dragut:
 * Suggested [JACKSON-850]: Allow use of zero-arg factory methods as "default creator"
  (2.1.0)

Duncan Atkinson:
 * Reported [JACKSON-851]: State corruption with ObjectWriter, DefaultPrettyPrinter
  (2.1.0)

Mark Wolfe:
 * Suggested #45: Add `@JsonNaming()` for per-class naming strategy overrides
  (2.1.0)

Dmitry Katsubo:
 * Contributed patch for #65: Add getters to `ObjectMapper`, DeserializationContext,
   DeserializationFactory.
  (2.1.0)

Francis Galiegue:
 * Reported #93 (and suggested fix): bug in `ObjectMapper.setAll(...)'
  implementation
  (2.1.1)
 * Reported #433: `ObjectMapper`'s `.valueToTree()` wraps `JsonSerializable` objects
  into a POJONode
  (2.3.3)
 * Contributed #434: Ensure that DecimalNodes with mathematically equal values are equal
  (2.4.0)

kelaneren@github:
 * Reported #157, contributed unit test: NPE when registering same module twice.
  (2.1.4)

Eric Tschetter (cheddar@github):
  * Reported issues #166, #167, #170 (regressions from 1.9.x to 2.x)
   (2.1.4)

Thierry D (thierryd@github)
  * Reported #214: Problem with LICENSE, NOTICE, Android packaging
   (2.2.2)

Luke G-H (lukegh@github)
  * Reported #223: Duplicated nulls with @JsonFormat(shape=Shape.ARRAY)
   (2.2.2)

Karl Moore (karldmoore@github)
  * Reported #217: JsonProcessingExceptions not all wrapped as expected
   (2.2.2)

David Phillips:
  * Requested #308: Improve serialization and deserialization speed of `java.util.UUID`
   (2.3.0)

Seth Pellegrino (jivesoft):
  * Contributed #317: Fix `JsonNode` support for nulls bound to	`ObjectNode`, `ArrayNode`
   (2.3.0)

Florian Schoppmann (fschopp@github)
  * Reported #358: `IterableSerializer` ignoring	annotated content serializer
   (2.3.1)
  * Reported #359: Converted object not using explicitly annotated serializer
   (2.4.0)

Martin Traverso:
  * Reported #406: Cannot use external type id + @JsonTypeIdResolver
   (2.3.2)

Matthew Morrissette:
  * Contributed #381: Allow inlining/unwrapping of value from single-component JSON array
   (2.4.0)

Will Palmeri: (wpalmeri@github)
  * Contributed #407: Make array and Collection serializers use configured value null handler
   (2.4.0)

Cemalettin Koc: (cemo@github)
  * Reported #353: Problems with polymorphic types, `JsonNode` (related to #88)
   (2.4.0)

Ben Fagin: (UnquietCode@github)
  * Suggested #442: Make `@JsonUnwrapped` indicate property inclusion
   (2.4.0)
  * Contributed #81/#455: Allow use of @JsonUnwrapped with typed (@JsonTypeInfo) classes,
    provided that (new) feature `SerializationFeature.FAIL_ON_UNWRAPPED_TYPE_IDENTIFIERS`
    is disabled
   (2.4.0)

Chris Cleveland:
  * Suggested #463: Add 'JsonNode.asText(String defaultValue)`
   (2.4.0)

Benson Margulies:
  * Reported #467: Unwanted POJO's embedded in tree via serialization to tree
   (2.4.0)
  * Reported #601: ClassCastException for a custom serializer for enum key in `EnumMap`
   (2.4.4)
  * Contributed 944: Failure to use custom deserializer for key deserializer
   (2.6.3)

Steve Sanbeg: (sanbeg@github)
  * Contributed #482: Make date parsing error behavior consistent with JDK
   (2.4.1)

Ian Barfield: (tea-dragon@github)
  * Reported #580: delegate deserializers choke on a (single) abstract/polymorphic parameter
   (2.4.4)
  * Reported #844: Using JsonCreator still causes invalid path references in JsonMappingException
   (2.5.5)

Eugene Lukash
  * Reported #592: Wrong `TokenBuffer` delegate deserialization using `@JsonCreator`
   (2.4.4)

Fernando Otero (zeitos@github)
  * Contributed fix for #610: Problem with forward reference in hierarchies
   (2.4.4)

Lovro Pandžić (lpandzic@github)
  * Reported #421: @JsonCreator not used in case of multiple creators with parameter names
   (2.5.0)

Adam Stroud (adstro@github)
  * Contributed	#576: Add fluent API for adding mixins
   (2.5.0)

David Fleeman (fleebytes@github)
  * Contributed #528 implementation: Add support for `JsonType.As.EXISTING_PROPERTY`
   (2.5.0)

Aurélien Leboulanger (herau@github)
  * Contributed improvement for #597: Improve error messaging for cases	where JSON Creator
    returns null (which is illegal)
   (2.5.0)

Michael Spiegel (mspiegel@githib)
  * Contributed #636: `ClassNotFoundException` for classes not (yet) needed during serialization
   (2.5.0)

Michael Ressler (mressler@github)
  * Contributed #566: Add support for case-insensitive deserialization
   (`MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES`)
   (2.5.0)

Konstantin Labun (kulabun@github)
  * Reported #647: Deserialization fails when @JsonUnwrapped property contains an object with same property name
   (2.5.0)

Christopher Smith (chrylis@github)
  * Reported #594: `@JsonValue` on enum not used when enum value is a Map key
   (2.5.0)

Alexandre Santana Campelo (alexqi200@github):
  * Contributed #671: Adding `java.util.Currency` deserialization support for maps
   (2.5.1)

Zoltan Farkas (zolyfarkas@github)
  * Reported #674: Spring CGLIB proxies not handled as intended
   (2.5.1)

Ludevik@github:
  * Reported #682: Class<?>-valued Map keys not serialized properly
   (2.5.1)

Antibrumm@github:
  * Reported #691: Jackson 2.5.0. NullSerializer for MapProperty failing
   (2.5.2)

Shumpei Akai (flexfrank@github)
  * Reported #703: Multiple calls to ObjectMapper#canSerialize(Object.class) returns different values
   (2.5.2)

Francisco A. Lozano (flozano@github)
  * Contributed fix for #703 (see above)
   (2.5.2)

Dylan Scott (dylanscott@github)
  * Reported #738: #738: @JsonTypeInfo non-deterministically ignored in 2.5.1 (concurrency
    issue)
   (2.5.2)

Alain Gilbert (agilbert314@github)
  * Reporter, contributed #766: Fix Infinite recursion (StackOverflowError) when
    serializing a SOAP object
   (2.5.3)

Alexey Gavrilov (Alexey1Gavrilov@github)
  * Reported, contributed fix for #761: Builder deserializer: in-compatible type exception
    when return type is super type
   (2.5.3)

Dmitry Spikhalskiy (Spikhalskiy@github)
  * Reported #731, suggested the way to fix it: XmlAdapter result marshaling error in
    case of ValueType=Object
   (2.5.3)

John Meyer (jpmeyer@github)
  * Reported, contributed fix for #745: EnumDeserializer.deserializerForCreator() fails
    when used to deserialize a Map key
   (2.5.3)

Andrew Duckett (andrewduckett@github)
  * Reported #771: Annotation bundles ignored when added to Mixin
   (2.5.4)

Charles Allen:
  * Contributed #785: Add handlings for classes which are available in
    `Thread.currentThread().getContextClassLoader()`
   (2.5.4)

Andrew Goodale (newyankeecodeshop@github)
  * Contributed #816: Allow date-only ISO strings to have no time zone
   (2.5.4)

Kamil Benedykciński (Kamil-Benedykcinski@github)
  * Contributed #801: Using `@JsonCreator` cause generating invalid path reference
   in `JsonMappingException`
   (2.5.4)

Chi Kim (chikim79@github)
  * Reported #878: serializeWithType on BeanSerializer does not setCurrentValue
   (2.5.5 / 2.6.1)

Charles Allen (drcrallen@github):
  * Reported #696: Copy constructor does not preserve `_injectableValues`
   (2.6.0)

Chris Pimlott (pimlottc@github):
  * Suggested #348: ObjectMapper.valueToTree does not work with @JsonRawValue
   (2.6.0)

Laird Nelson (ljnelson@github)
  * Suggested #688: Provide a means for an ObjectMapper to discover mixin annotation
    classes on demand
   (2.6.0)

Derk Norton (derknorton@github)
  * Suggested #689: Add `ObjectMapper.setDefaultPrettyPrinter(PrettyPrinter)`
   (2.6.0)

Michal Letynski (mletynski@github)
  * Suggested #296: Serialization of transient fields with public getters (add
    MapperFeature.PROPAGATE_TRANSIENT_MARKER)
   (2.6.0)

Jeff Schnitzer (stickfigure@github)
  * Suggested #504: Add `DeserializationFeature.USE_LONG_FOR_INTS`
   (2.6.0)

Jerry Yang (islanderman@github)
  * Contributed #820: Add new method for `ObjectReader`, to bind from JSON Pointer position
   (2.6.0)

Lars Pfannenschmidt (larsp@github)
  * Contributed #826: Replaced synchronized HashMap with ConcurrentHashMap in
   TypeDeserializerBase._findDeserializer
   (2.6.0)

Stephen A. Goss (thezerobit@github)
  * Contributed #828: Respect DeserializationFeatures.WRAP_EXCEPTIONS in CollectionDeserializer
   (2.6.0)

Andy Wilkinson (wilkinsona@github)
  * Reported #889: Configuring an ObjectMapper's DateFormat changes time zone
   (2.6.1)

lufe66@github:
  * Reported 894: When using withFactory on ObjectMapper, the created Factory has a TypeParser
    which still has the original Factory
   (2.6.2)

Daniel Walker (dsw2127@github)
  * Reported, contributed fix for #913: `ObjectMapper.copy()` does not preserve
   `MappingJsonFactory` features
   (2.6.2)

Sadayuki Furuhashi (frsyuki@github)
  * Reported #941: Deserialization from "{}" to ObjectNode field causes
    "out of END_OBJECT token" error
   (2.6.3)

Sergio Mira (Sergio-Mira@github)
  * Contributed #940: Add missing `hashCode()` implementations for `JsonNode` types that did not have them
   (2.6.3)

Andreas Pieber (anpieber@github)
  * Reported #939: Regression: DateConversionError in 2.6.x	
   (2.6.3)

Jesse Wilson (swankjesse@github)
  * Contributed #949: Report the offending substring when number parsing fails
   (2.6.3)

Warren Bloomer (stormboy@github)
  * Reported #942: Handle null type id for polymorphic values that use external type id
   (2.6.3)
