Here are people who have contributed to development of json-forms:
(version numbers in brackets indicate release in which the problem was fixed)

fabifabi@github
Several contributions regarding i18n. French translation
(1.6.2)

Omri Schwarz (ocschwar@github):
#23: $ref, definitions, fixed oneOf, patternProperties
(1.4.0)

Stephen J. Fuhry (fuhrysteve@github)
#20: Add support for date format 
(1.3.1)

Matheus Graciano (graciano@github)
#16: Propperly adding types to buttons
(1.2.4)

Volt220@github
#15: Update brutusin-json-forms.css
(1.2.3)

Dirk Haage (e110c0@github)
#14 Added version to package.json
(1.2.1)

Omri Schwarz (ocschwar@github):
#11: Add handling for the oneOf option for schemas
(1.2.0)