#!/usr/bin/env perl -l

use strict;
use warnings;

my %data;
my $re = qr{^(\w+\s+\w+)\s+(\w+)\s+(\w+)};

while (<DATA>) {
    my ($key, $val) = map { $_->[0], join ':', @$_[1,2] } [/$re/];
    push @{$data{$key}}, $val;
}

print "$_ ", join ', ', @{$data{$_}} for sort keys %data;

__DATA__
id1    name1 cat1  catname1
id1    name1 cat2  catname2
id2    name2 cat3  catname3
id3    name3 cat1  catname1
id3    name3 cat4  catname4