I just tried building a blank app with node-webkit, and the .app file came to around 100MB. It includes the whole Node/Chromium runtime thing.

With MacGap it's only 1MB for a blank app, apparently. It presumably uses OS X webviews, which don't need to be distributed with it.

Obviously node-webkit has a lot more things going for it, like Node/NPM, and cross-platform support. But the size thing does matter. If you are making a basic little utility app, people are going to be suspicious of a very large download size.

From the docs, "The project exposes a JavaScript API for OS X integration, such as displaying native OS X 10.9 notifications."

The set of extra OSX-related facilities appears to be pretty limited for now. Apart from that, it also uses Webkit, but it uses the one provided by OSX, so it does not need to be distributed with your application. The coolest thing would be if node-webkit could also use OSX's Webkit API, but that seems improbable since it's Objective-C only.

It's one megabyte instead of 80.

This version is Mac App Store compatible.