ES_Interrupt

 Description:
Simple addon to keep track of your partymembers interrupt-cooldowns.

– Chat commands:
/esi toggle (enable/disable)
/esi lock (lock/unlock)
/esi reset (reset position and unlock)

– To display numbers on the timersweep, enable the default Blizzard setting:
Interface -> ActionBars -> "Show Numbers for Cooldowns"
Personally, I use the addon OmniCC to enhance the visual on timers instead of blizzards default option.

Note!

Warlocks (both the player himself, and partymembers) have checks in the code that use ability names.
These have beeen translated and should work for all localizations.

If translations are wrong, thus giving you issues or causing unexpected behaviour, please report the incident. 

! To report issues, visit the project page.

Known issue:
Due to limitation of extracting info from partymembers, I could not find a reliable way of telling if a warlock's "Command Demon" has "Spell Lock" while using Grimoire of Sacrifice.

– This means that the addon will default to show warlocks as having interrupt while using specialization Affliction and Destruction (with Felhunter, or no pet), and not having interrupt as Demonology.

For the player himself, it will update correctly depending on your available interrupt.