- Open Directory Computers: Software: Operating Systems: Extensible
- Open Directory Computers: Software: Operating Systems: Open Source
- Open Directory Computers: Software: Operating Systems: Network: Open Source
- Open Directory Computers: Software: Operating Systems: Network: Distributed
- Open Directory Computers: Software: Operating Systems: Embedded
- Open Directory Computers: Software: Operating Systems: Single Address Space
- Open Directory Computers: Software: Operating Systems: Realtime
- Open Directory Computers: Software: Operating Systems: Monolithic: Hybrid
- Open Directory Computers: Software: Operating Systems: Research