Results of compression
Now that you're all learned up on javascript and css compression, let's see exactly what the savings are.
jQuery - version 1.2.6 (97.8 KB)
- PACKER: 30.0 KB
- Min: 54.9 KB -- 17 KB with gzip enabled
- YUI: 54.1 KB -- 17 KB with gzip enabled
Prototype - version 1.6.0.2 (124 KB)
- PACKER: 46.5 KB
- Min: 91.7 KB -- 24 KB with gzip enables
- YUI: 71.7 KB -- 22 KB with gzip enabled
MooTools - 1.2 Core (94.2 KB)
- PACKER: 40.7 KB
- Min: 74.0 KB -- 21 KB with gzip enabled
- YUI: 61.3 KB -- 20 KB with gzip enabled
Dojo - version 1.1.1 (just the core dojo.js.uncompressed.js - 259.0 KB)
- PACKER: 48.5 KB
- Min: 81.8 KB -- 26 KB with gzip enabled
- YUI: 80.1 KB -- 25 KB with gzip enabled
What should you use?
It really comes down to what library you like, and what your web-server will allow. Personally I favor YUI, without using gzip YUI gives you better compression than min, and I really like the white-space intelligence algorithm it has built in to it. PACKER is still not a bad option and it's what I use on my hosted server (since they do not allow gzip/deflate), so if you're in my boat that's really the only way to go.
As far as what library to use I was really surprised. It turns out that when you compress your js, and then enable gzip/deflate on your server, every library comes out on almost equal footing. So find the library you love, and go to town.