Below are a comparison (copy/pasted from the source) of the different Sync tools from Microsoft. It was updated on September 5, 2014. To be absolutely updated go to
http://msdn.microsoft.com/en-us/library/azure/dn798669.aspx since things will change over time.
On-Premises to Cloud Synchronization
| Feature | Azure Active Directory Synchronization Tool (DirSync) | Azure Active Directory Synchronization Services (AAD Sync) | Forefront Identity Manager 2010 R2 (FIM) |
| Connect to single on-premises AD forest | X | X | X |
| Connect to multiple on-premises AD forests |
| X | X |
| Connect to single on-premises LDAP directory (no AD at all) |
| CS | X |
| Connect to multiple on-premises LDAP directories |
| CS | X |
| Connect to on-premises AD and on-premises LDAP directories |
| CS | X |
| Connect to custom systems (i.e. SQL, Oracle, MySQL, etc.). |
| CS | X |
| Synchronize customer defined attributes (directory extensions) | CS | CS |
|
Cloud to On-Premises Synchronization
| Feature | Azure Active Directory Synchronization Tool (DirSync) | Azure Active Directory Synchronization Services (AAD Sync) | Forefront Identity Manager 2010 R2 (FIM) |
| Write-back of devices | X | CS |
|
| Attribute write back (for Exchange hybrid deployment ) | X | X | X |
| Write-back of users, groups objects | CS | CS |
|
| Write-back of passwords (from SSPR and password change) | CS | CS |
|
| Write-back of customer defined attributes (directory extensions) | CS | CS |
|
Authentication Feature Support
| Feature | Azure Active Directory Synchronization Tool (DirSync) | Azure Active Directory Synchronization Services (AAD Sync) | Forefront Identity Manager 2010 R2 (FIM) |
| Password Hash Sync for single on-premises AD forest | X | CS |
|
| Password Hash Sync for multiple on-premises AD forests |
| CS |
|
| Federation (SSO) | X | X | X |
Set-up and Installation
| Feature | Azure Active Directory Synchronization Tool (DirSync) | Azure Active Directory Synchronization Services (AAD Sync) | Forefront Identity Manager 2010 R2 (FIM) |
| Supports installation on a Domain Controller | X | X |
|
| Supports installation using SQL Express | X | X |
|
| Step-up from DirSync to AADSync |
|
|
|
| Localization Windows Server languages) | X | CS |
|
| Support for Windows Server 2008 and Windows Server 2008 R2 | X | X | X |
| Support for Windows Server 2012 and Windows Server 2012 R2 | X | X |
|
Filtering and Configuration
| Feature | Azure Active Directory Synchronization Tool (DirSync) | Azure Active Directory Synchronization Services (AAD Sync) | Forefront Identity Manager 2010 R2 (FIM) |
| Filter on Domains and Organizational Units | X | X | X |
| Filter on attribute values on objects | X | X | X |
| Allow minimal set of attributes to be synchronized "MinSync" |
| X |
|
| Allow different service templates to be applied for attribute flows |
| X |
|
| Allow removing attributes from flowing from AD to AAD |
| X |
|
| Allow advanced customization for attribute flows |
| X | X |
