This is a unofficial overview of the present Linux Certifications that I know of. If you have feedback on this overview to improve it. Please let me know.

1. Geniric Specific to Linux distibution
LPI LET LPI Essentials (from June 2012)
LPI Essentials (from June 2012)
Trainee LPI LET LET = Linux Essentials Technician
LET = Linux Essentials Technician
LPI 101
LPI 101 RHCSA RHCVA
Junior Suse CLA CompTIA RHCSA RHCVA
LPIC-1
LPIC-1 Certified Linux Administrator Linux + LPI
RedHat RedHat
RedHat
Certified RedHat
Certified
Certified Certified
LPI 102
LPI 102
System
System
Administrator
Virtualisation
Virtualisation
Administrator
Administrator Administrator
Univention
Univention Suse CLP
Suse CLP Zarafa
Zarafa
UniVention Certified Prof Certified Linux Prof Zarafa Certified Engineer
UniVention Certified Prof Certified Linux Prof Zarafa Certified Engineer
RHCE
RHCE
Redhat Certified Engineer
LPI 201
LPI 201 Suse
Suse
Redhat Certified Engineer
LPIC-2 CLE
CLE
LPIC-2 Certified
LPI 202
LPI 202 LinuxCertified
Engineer
Linux Engineer
LPI
LPI
301 LPI
LPI LPI
LPI LPI
LPI LPI
LPI RHCA RHCSS RHCDS
301
OpenLDAP 302 303 304 310 RHCA RHCSS RHCDS
RedHat RedHat RedHat
LPIC-3
LPIC-3
OpenLDAP 302 303 304 310 RedHat RedHat RedHat
Expert &
&
Capacity
Mixed
Mixed
Security
Security
High
High
Mixed
Mixed
Certified
Certified
Architect
Certified
Certified
Security
Certified
Certified
Datacenter
Capacity Environment Availability Environment Architect Security
Specialist Datacenter
Specialist
Planning Environment
(Samba3) Availability (Samba4)
& Environment Specialist Specialist
Planning (Samba3) & (Samba4)
Virtualisation
Virtualisation
Emiel Brok