The Apache Directory Server is an embeddable LDAP server implemented in pure Java. It has several features that make it unique among LDAP servers. Some of these featurea are as follows:
| ApacheDS | Fedora DS | OpenLDAP | OpenDS | |
|---|---|---|---|---|
| Website | directory.apache.org | directory.fedoraproject.org/ | openldap.org | opends.org |
| License | Apache License 2.0 | GNU General Public License | OpenLDAP Public License | Common Development and Distribution License |
| Documentation | minimal | extensive | sufficient | extensive |
| Code | Java | C/C++ | C/C++ | Java |
| Backed by organization | Apache Software Foundation | RedHat | OpenLDAP Foundation | Sun |
| Origin | genuine | Netscape DS (Michigan university) | Michigan university | genuine |
| Admin Gui | no | yes | no | yes |
| Installation | Installer | Installer | Package/build | Installer |
| ApacheDS | Fedora DS | OpenLDAP | OpenDS | |
|---|---|---|---|---|
| Back-End | JDBM and custom | Berkeley DB | Berkeley DB and others | Berkeley DB Java Edition, NDB and memory |
| Multiple Back-Ends | yes | yes | yes | yes |
| Front-ends | LDAP, Kerberos, DNS, NTP, DHCP | LDAP, DSMLv2 (SOAP/HTTP) | LDAP/LDAPS | LDAP/LDAPS. DSMLv2 gateway (SOAP/HTTP) |
| Replication | Multi-Master (2 masters) ... soon | Multi-Master (up to 4 masters) | Single-Master | Multi-Master (up to 8 masters) |
| Referrals | yes | yes | yes | yes |
| Schema | Compilation | dynamic/gui | dynamic/ldap | dynamic/ldap/gui |
| Attribute Encryption | no | yes | no | no |
| Monitoring | LDAP | LDAP/SNMP | LDAP | LDAP/SNMP/JMX |