"In the crowded IT professional market, where having more than a
passing familiarity with open source software can open doors to
better jobs, few people will argue the benefit of acquiring open
source training and certification. But watch out where you get your
training information from.
"Many people choose to become certified in open source software
in order to increase their professional marketability or simply for
their own edification. Though certification program creators
typically recommend against it, most will allow people to sit for a
certifying exam without requiring pre-test coursework. There are
various methods of preparing for a certification exam, with the
most popular being online, textbook, and hands-on study..."