Mercurial: How I can use external tool for diff?

Question

I want to use kdiff3 as a tool for comparing different versions of a repository. Is there a way how one can do it?

Answer 1

I have found the answer and want to let it here in order not to forget:

Add to ~/.hgrc file the following sections:

[extensions]
hgext.extdiff =

[extdiff]
cmd.kdiff3 =

and then type:

hg kdiff3