Patching an OS X App Easily

Question

What's the simplest way to patch an OS X app not issued through the Mac App Store?

From what I've gathered, the "standard" way is via bsdiff and bspatch, but I've noticed that a bunch of programs have software patching screens that are essentially identical, so I was wondering if there was a tool of some sort out there that makes patching software easy?

Here's the screen I see, it's virtually the same for all the applications that have it- the buttons, wording, titles and everything are in the same- the only variation is the icon and the names & release notes.

It also goes through the same "downloading update, installing update" (and so on) prompts, the only variation being the icon of the app.

Answer 1

This is from the Sparkle framework:

http://sparkle.andymatuschak.org/

Answer 2

Many huge projects use the Sparkle framework for updates.