Package: rubygem-diff-lcs

"rubygem-diff-lcs" package binaries on CentOS:

/usr/bin/htmldiff /usr/bin/ldiff /usr/lib/ruby/gems/1.8/gems/diff-lcs-1.1.2/bin/htmldiff /usr/lib/ruby/gems/1.8/gems/diff-lcs-1.1.2/bin/ldiff

You may install this package on CentOS with yum install rubygem-diff-lcs