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

Tatu Saloranta (tatu.saloranta@iki.fi): author

Steven Schlansker (steven@nesscomputing.com): co-author

Stephan Schroevers: (Stephan202@github)
  * Contributed #56: Add support `HashCode`
   (2.5.0)
  * Contributed #65: Add deserialization support for SortedMultiset and ImmutableSortedMultiset
   (2.5.3)

Michael Hixson:
  * Contributed fix for #67: Support deserializing ImmutableSetMultimaps
   (2.6.0)

Alexey Kobyakov (akobiakov@github)
  * Reported #64: `@JsonUnwrapped` annotation is ignored when a field is an Optional
   (2.6.0)

Jose Thomas (josethomas@github)
  * Contributed #52: Guava collection types do not allow null values
   (2.6.2)

Jonathan Rodrigues de Oliveira (jorool@github)
  * Contributed #79: New configuration for Guava Range default bound type.
   (2.7.0)

Micahel Jameson (mjameson-se@github)
  * Reported #87: OSGi import missing for `com.fasterxml.jackson.annotation.JsonInclude$Value`
   (2.7.1)