Like some others out there, I am not a huge fan of Stacks and miss the Dock's old functionality (i.e. being able to browse folders' contents by Control-clicking). I thought to myself, "The Dock is just an application in the /System » Library » CoreServices folder, so can't I just use Tiger's Dock.app?"

When I upgraded to Leopard, I backed up to an external drive and did an Erase & Install so I had a copy of Tiger's Dock.app handy. I used both the Finder and Terminal to do the switch (but I'm sure you can use one or the other completely).

[robg adds: What follows should be considered highly experimental. Using the 10.4 dock in 10.5 may have unforeseen issues. If you choose to implement this hint, that decision is yours. Proceed cautiously, and make sure you've got a good backup before you start! Read on for the relatively simple how-to...]

Disclaimer: I used sudo in some steps. If you don't know about/feel comfortable using sudo, it's probably best not to.

1. Copy Tiger's Dock.app from the backup to the Desktop
2. In Terminal, fix the permissions if needed:

   $ sudo chown -R root /Users/[short user name]/Desktop/Dock.app
   $ sudo chgrp -R wheel /Users/[short user name]/Desktop/Dock.app

3. Make a folder called OldDock on the Desktop.
4. Kill the running Dock, move Leopard's Dock to OldDock, and move Tiger's Dock to CoreServices:

   sudo killall Dock && \
   sudo mv /System/Library/CoreServices/Dock.app /Users/short_user_name/Desktop/OldDock/ && \
   sudo mv /Users/short_user_name/Desktop/Dock.app /System/Library/CoreServices/

Note: Replace short_user_name with your user's short user name. Since Dock.app is a running application and will relaunch right after you kill it, I had to string together the Terminal commands in one line. But in any event, Tiger's Dock appears and Control-clicking folders works again! Applications launch as they should, folders behave as they did...

However, the black triangles indicating open apps don't work properly. If an application is running at the time Tiger's Dock is launched, it will have the indicator (e.g., Finder). But any other app that opens after the relaunch will look like it's not running. (It is running though: if you click on an app you know is open, it still brings it to the front as expected.) I'm guessing the old Dock polls open apps differently and that method is absent in Leopard.

As far as I can tell, this is the only misbehavior. Personally, I right-click folders in the Dock a lot, so I can deal. Plus I use LiteSwitch X to switch apps so I often don't pay attention to the open app indicators.