To obtain MySQL Enterprise, visit http://enterprise.mysql.com if you're a customer. Otherwise, visit http://www.mysql.com/products/enterprise/. The platforms that are officially supported for MySQL Enterprise are listed at http://www.mysql.com/support/supportedplatforms/enterprise.html.
MySQL Enterprise Server is available for download in the form of Quarterly Service Pack (QSP) or Monthly Rapid Update (MRU) binary releases.
To install MySQL Enterprise Server, you should use the latest available Quarterly Service Pack (QSP). This includes an accumulation of the bug fixes provided in all predecessor QSP and MRU releases.
MRU releases are provided on a monthly basis and represent the most current Enterprise Server bug fixes. Each MRU is an accumulation of the bug fixes included in its predecessor. Customers should standardize on the latest MRU release only if it includes a needed bug fix.