Shepherd started out as an extremely simple mod to fulfill a guildmate's request: Call our MT a moron whenever he broke a sheep. It has since evolved into one of the most advanced crowd control addons, at least of the ones that the author has been able to find :)
Don't let the name fool you, Shepherd can also track shackle, hibernate, and sap. It allows you to define arbitrary filters on what to say to people who break your crowd control, and where to say it. Things it has over simple "aura dispelled" event watching:
Tracks who used which crowd control spells on what mobs. This means you can include that person's name if you wish, or automatically send them a whisper (great for raid leaders).
Detects if you or your party are actively being attacked by enemies. Once a configurable amount of time has passed, crowd-control breaks are assumed to be on purpose and are not reported to the group. This helps prevent people from getting annoyed with you for spamming chat unnecessarily when you move on to the next target. The default configuration still shows you the details on your local console.
Coordinates with other people in your group who are also running Shepherd. If multiple people are configured to send messages to the same channel, one will be selected to report it and the rest will be silent, preventing chat spam. Also avoids sending whispers to people who have Shepherd and presumably already know about it.
Shepherd is extremely flexible and all of the points above can be changed or configured to your liking. It includes a set of default rules with sensible settings that can simply be enabled or disabled. If you want more control, a wide range of options are possible.
Now that the marketing spiel's out of the way, here's the lowdown. There's a 1.6 version of Shepherd on curse that is considered the stable release. The one here on wowace is my development version and will become 2.0. It is completely revamped and much more configurable and flexible, but hasn't undergone as much real world bug testing. That said, it's what I'm using when I raid so it's at least in working order :)
Things that I still need to do include rewriting the documentation for 2.0 and setting up a wiki page with screenshots and info and such. Unlike 1.6, this version should be possible to localize. I'm still tweaking the configuration options and will likely rearrange things, relabel things, and rewrite sections of text to clarify them. Translate if you wish but be warned that it may change out from under you at any moment :D
There's no documentation on the new configuration screens yet, so if you're having trouble, post here and I'll try to answer any questions. That will also help me figure out what I need to document and what are possible problem areas that can be clarified in the UI.
Q: How do I configure this thing?
A: /shepherd or /tsb
It also adds itself to the Blizzard UI panel under addons, but DON'T USE IT! The layout gets horribly cramped and it almost impossible to use.
Q: Are hunter freezing traps supported?
A: Unfortunately, no. The combat log doesn't currently provide enough information to get the level of quality I want in making reports. Basically it's not possible to tie a particular mob getting trapped to the hunter who placed the trap. Suggestions for a way to do this are of course welcome.
Q: What are all these rules?
A: Think of them like filters in your email client. When a crowd control spell gets broken, it starts at the top and works its way down looking for a rule that matches. There's a "Stop Here" checkbox that causes any rules after the one that matches to not get processed, if you uncheck it, it's quite possible to send multiple messages. There is also an "Always Run" checkbox that overrides a previous "Stop Here", but only for that one rule.
Q: Aren't checking "Always Run" and unchecking "Stop Here" redundant?
They don't quite do the same thing. Always Run also overrides the group synchronization, so a rule that has Always Run checked will send the message even if someone else in your group does also. It's a way to spam regardless if you really want to.
Q: Does it work in PvP?
Of course! What I refer to as 'mob' may actually be any target that is considered hostile (or neutral) to you. Most of the default rules are disabled in battlegrounds, but can be re-enabled if you wish.
I'll look into adding this (this blizzard ones anyway, don't have much experience with oRA). In the meantime you can always use the 'except by specific players' option on your rules to exclude them by name. It's not quite as convenient since you have to change it for each raid, but it should do what you want.
EDIT: On second though a better way might be to create a new rule at the top of your list. Call it 'Main Tanks'. Set the message to display on your local chat frame only, and make sure the 'Stop Here' is checked. Set the filter to alert you when Specific Player(s) break CC by anyone, and put the main tank or tanks' name in.
That way you only have to change the name in 1 rule instead of however many other complex ones you have.