patches in general

[Glenn F. Leavell]

I ocassionaly see "patches" to various programs.  Here's a piece of one that
I recently saw:

>***************
>*** 7,10 ****
>  sites wishing to support them and finding a feed.  In general, these
>! groups are not carried by the entire network due to their volume, a
>! restricted sphere of interest, or a different set of administrative
>  rules and concerns.
>--- 7,10 ----
>  sites wishing to support them and finding a feed.  In general, these
>! groups are not carried by the entire network because of their volume,
>! restricted spheres of interest, or a different set of administrative
>  rules and concerns.
>***************

This doesn't look like standard diff stuff, so my question is, what package
or utility is used to merge these changes with the original document?

Thanks for any help,
Glenn Leavell
glenn at rigel.econ.uga.edu