"Currently, there are vendor-neutral certifications in
Linux available from two sources: LPI (Linux Professional
Institute) and Sair. To become LPI certified at the first level --
the only one currently available -- you must pass a series of two
exams. With Sair, to become certified as a Linux Certified
Administrator (LCA), you must pass four exams (passing Installation
and Configuration 101 by itself will earn you the designation of
Linux Certified Professional).
This summer, CompTIA will add another Linux certification to the
fray -- that of Linux+ (pronounced "Linux plus"). This is a
one-exam certification -- good for life -- on vendor-neutral topics
similar to the other two certifications. Beta testing began June
22nd and will continue for one month. The live exam is scheduled to
appear later in the summer (most likely in September).
CompTIA is the Computing Technology Industry Association and is
most well known for the A+ hardware certification (260,000+
certified). Other CompTIA certifications have followed in recent
years -- all ending with the "plus" designation: Network+, i-Net+,
and most recently Server+."