Linux 27 Examinations 22 Certification 20 Electronic data processing personnel 19 Operating systems (Computers) 16 Systems engineering 8 Red Hat, Inc 6 Automation 5 Information technology 5 Management 5 Application software 4 Cloud computing 4 Computer security 4 Development 4 Virtual computer systems 4 Application program interfaces (Computer software) 3 Computer programming 3 Computer networks 2 Open source software 2 Command languages (Computer science) 1 Computer programmers 1 Linux device drivers (Computer programs) 1 OpenStack (Electronic resource) 1 RPM (Computer file) 1 UNIX (Computer file) 1 Ubuntu (Electronic resource) 1 VMware vSphere 1