Linux Core
- Systems & network administration
- Performance tuning
- Troubleshooting & debugging
- Realtime (PREEMPT_RT)
Migrations
- Various virtualization platforms to XEN
- Windows NT/2000/2003 to Linux & Samba 3.0
- Novell Netware to Novell Open Enterprise Server
- SUSE Manager 2.x to SUSE Manager 3
Applications & Services
- Apache
- Samba
- OpenLDAP
- Postfix/Sendmail
- AutoYaST/Kickstart
- Open Build Service
- Pacemaker
- drbd
- HAProxy
- Linux Virtual Server
- Ceph
- Nagios
- Jenkins
- Salt
- Puppet
- Ansible
- Katello
- SUSE Manager
- Red Hat Satellite
- Spacewalk
- Hadoop
Cloud
- OpenStack
- SUSE OpenStack Cloud
- Mirantis OpenStack
- Red Hat OpenStack Platform
Virtualization
- Docker Swarm
- Kubernetes
- OpenShift
- Xen/XenEnterprise
- Kernel-based Virtual Machine (KVM)
- Docker container management
- LXC Container Backend
Databases
- MariaDB
- MongoDB
- CouchDB
- MySQL
- Oracle
- PostgreSQL
- SQLite
GNU/Linux Distributions, Commercial Products & UNIX Operating Systems
- SUSE Linux Enterprise Server (SLES)
- SUSE Linux Enterprise Desktop (SLED)
- SUSE Linux Enterprise High Availability Extension (SLE HAE)
- SUSE Linux Enterprise Realtime (SLERT)
- SUSE Manager
- SUSE Container as a Service Platform
- SUSE Enterprise Storage
- Novell Open Enterprise Server
- Novell Open Enterprise Server 2
- Red Hat Enterprise Linux (RHEL)
- Red Hat Enterprise MRG (Messaging, Realtime, and Grid)
- Red Hat High Availability Add-on
- Red Hat Resilient Storage Add-on
- Red Hat Ceph Storage
- Red Hat Gluster Storage
- Red Hat OpenShift Container Platform
- Red Hat Satellite
- Debian
- Ubuntu
- CentOS
- miscellaneous Linux distributions
- AIX/LPAR
- Solaris
- openSolaris
Programming & Scripting
- C
- C++
- Perl
- Python
- Java
- Ruby
- HTML
- XML
- XSLT
- PHP
- Shell (ksh/bash)
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