Joomla3-Admin-template/joomla-cms — pull request #110 by nternetinspired (2012-08-14 11:11:24+00:00)
Title: Forces IE to use the latest rendering engine

If IE 8/9 is in compatibilty mode it isn't possible to login to
/administrator. This meta forces IE to uses the latest available
rendering engine, switching it out of compatibility mode even if the
user already has it enabled, allowing them to login.