How did I not know how wonderful this was before? It’s not like it just came out yesterday. And it’s free!!

Fluid is an application you can use to create Site Specific Browsers (SSBs) on the Mac based on the Safari rendering engine (WebKit). The author freely admits that the concept was inspired by Mozilla Prism, which does something similar for Firefox and its rendering engine, Gecko. As well as Adobe AIR which brings its own tricks to the party beyond just duplicating a browser.

The beauty of a browser like Google Chrome is that each tab runs in its own space in memory. If a web app misbehaves, you can shut down that tab and free up its resources without bringing down the whole browser. Fluid brings a similar concept to the Mac in an oh-so-elegant way that relieves most of the pain I had in switching from Firefox to Safari.

As a matter of fact, I tried the latest Firefox release candidate the other day and found that I still prefer Safari for day-to-day use. Fluid-created SSBs make the experience near perfect for me.

It’s simple. When you launch the application you just tell it which page should now be treated as a stand-alone application.

You can use the icon from the page’s website, or point it towards a PNG file of your own. So far, I’ve created SSBs for my task manager (RTM), my 2 main Google email accounts, my timesheet & expense application (Clicktime), Salesforce, Convio Admin, Box.net, and my feed reader (Fever). Convio in particular is tons faster running as a SSB than it is in any browser. You can tweak the behavior of each SSB in preferences, controlling its layout, tab behavior & navigation.

This is way more than a simple desktop shortcut for getting to a website. I no longer have to be concerned about keeping my mail tabs accessible in Safari. They’re always open and not in the way of my other browsing. Even better, I can delete the cache of any SSB without affecting the cache of other pages.

Here are some other features that I am loving:

Apps can have dock badges! This is killer. There’s a Javascript API for developers to add this functionality. Unread indicators for Gmail, Yahoo! Mail, Facebook are built in to Fluid. So I was easily able to create separate SSBs for both of my main Gmail email accounts, using images for the icons that help me tell them apart. If I had any feeds set to show unread counts, I’d see that in the Fever icon, too:

Support for userscripts.org. It’s kind of like Greasemonkey for WebKit/Safari. I can’t use the Better Gmail extension I loved from Firefox, but I can easily add some of the scripts (not all work) to my mail browsing experience in their SSB. Proceed with caution here and only install scripts you know/trust. Some can be nasty/dangerous. There are some specifically designed to add the necessary Javascript code for dock badges in Fluid.

Turn a web app into a MenuExtra. You know, those little icons at the top of the screen? There are some web apps that you want accessible no matter where you are, rather than breaking your concentration and switching to a completely new application. Simply select “Convert to MenuExtra SSB…” from the application menu. Of course, you wouldn’t want a big honkin’ screen to pop up there, so I think it’s better to use mobile interfaces. I use it for Remember the Milk, using their iPhone view. On second thought, it’s much better to use the Google iGadget for RTM

Anyone else using Fluid and have any tips & tricks to share with me?