Microsoft Dynamics CRM 2013 SP1 4 releases in one. For
Microsoft Dynamics CRM Online, this release is referred to as CRM Online Spring
'14.
Over the past year, Microsoft acquired three companies to
bring significant enhancements to marketing planning, social media marketing,
and customer service functionality to its Dynamics CRM.
To download SP1 for 2013 click on the below link
To get more details on the releases click here
To know about the Known issues click here