Here's something that could help:
http://svn.tools.ietf.org/tools/rfcdiff/
I don't like their colors, but that should be easy to change.
On Thu, Jun 11, 2009 at 3:03 PM, Jakub Narebski<jnareb@gmail.com> wrote:
Show 20 quoted lines
> E R <pc88mxer@gmail.com> writes:
>
>> Is there a a side-by-side diff viewer for gitweb?
>
> No, it is for a long time on TODO list for gitweb, but it never got
> implemented.
>
>> If not, any suggestions for the best way to go about implementing one?
>
> Take a look at other web interfaces in Perl, and find how they do it
> (IIRC Codestriker web review tool is in Perl, and has side-by-side
> diffs). Ask on #perl. Ask on perlmongers. Search CPAN[1].
>
> [1] Note that we frown upon introducing extra dependencies for gitweb,
> unless they are optional, and best detected automatically.
> --
> Jakub Narebski
> Poland
> ShadeHawk on #git
>