libjson-perl 4.02000-1ubuntu1 (amd64 binary) in ubuntu focal

 JSON is a Perl module for manipulating data stored in the format of the same
 name. JavaScript Object Notation (JSON) is a simple data serialization format
 (defined in RFC 4627) that serves as an alternative to XML.
 .
 The primary purpose of this module is to select an appropriate backend JSON
 implementation. It prefers either JSON::XS (see libjson-xs-perl) or JSON::PP
 (see libjson-pp-perl), but will fall back on a backport implementation if
 neither are available.