Rated 5 out of 5 stars

To install this Add-on for FF 3.6.x
(works just fine-I'm using 3.6.6 on Mac OS X 10.4.11):

1. install MR Tech Toolkit.
https://addons.mozilla.org/en-US/firefox/addon/421/

2. Once installed, go to preferences under "Miscellaneous". Click on the tab for "XPI Install Options" and UNCHECK "Enable Addons Compatibility Checking".
NOTE: This turns off checking for ALL extensions (but you will only do this temporarily--see step 5 below).

There may be other add-ons that can turn this checking off but MR Tech Toolkit is the only one I know. This step is critical to be able to download FIT addon.

3. Now install this add-on from here.

4. Once Find in Tabs is installed, go to the Extensions list, find "Find In Tabs" extension. Right-click and select "Make Compatible" (this only applies to the add-on selected). Now this add-on will be enabled when you restart FF 3.6.x.

5. Now we have to re-enable Add-on Compatibility Checking for the rest of the add-ons. Just reverse the steps in step 2. by re-checking the "Enable Addons Compatibility Checking".

Rated 3 out of 5 stars

Please, Please PLEASE update for FF3.6 +

This is one of the best ways to search across multiple tabs and the presentation of the results is very practical.

The closest alternative I have been able to find is Tabhunter.
https://addons.mozilla.org/en-US/firefox/addon/7924/

Its benefit is that it actually searches across all tabs in ALL windows. Its con is that the presentation of the results is not the best. Also clicking on a result takes you to the tab BUT does not highlight the results, so you have to perform another Find.

As for Find IN Tabs, when the divider line is moved down, you only get grey space, the window split does not adjust.

If you try to move up, it shrinks the other frame, BUT if you move the split back it does not grow back.

There are also some incompatibilities I have pointed out before (see my previous review).

I am using FF 3.5.10 & OS X 10.4.11 but would like to move to FF 3.6 +

Rated 3 out of 5 stars

Works very well. Would be nice to be able to resize the results area by moving the horizontal window divider up or down.

I have a 24" screen with 1900x1200 resolution and the results area is almost half the window using too much space.

Other incompatibilities exist with other Find extensions:
Find All
Find Toolbar Tweaks (This may actually be their fault as FTT does not work well with others also)

Compatibility checker still reports issues with other extensions even if they are Disabled within the Extension Manager in FF.

Would be nice if had option to toggle Find In ALL Tabs vs Find in Current Tab

I am using FF 3.5.3 on Mac OS X 10.4.11