The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Poetry (5 members)
- Politics (90 members)
- Ports (25 members)
- Potrock (1 member)
- Privacy (51 members)
- Programming (58 members)
- Programming Languages (33 members)
- Programs (87 members)
- Protocols (40 members)
- Psychology (80 members)
- Public domain images (18 members)
- Punk (13 members)
- Python (9 members)
- Quotes (12 members)
- Random (65 members)
- Reasons to boycott the music industry (9 members)
- Religion (89 members)
- Robert Anton Wilson (48 members)
- Routing (11 members)
- SSL (2 members)
- Satire (4 members)
- Science (99 members)
- Science Fiction (14 members)
- Scripts (35 members)
- Scripts (UNIX) (5 members)
- Searches (22 members)
- Second Life (2 members)
- Security (24 members)
- Select category (1 member)
- Seti (28 members)
- Sex (1 member)
- Social Software (10 members)
- Social software (1 member)
- Socialism (0 members)
- Sociology (8 members)
- Software (209 members)
- Solaris (24 members)
- Solaris 10 (5 members)
- Solaris Networking (7 members)
- Solaris Zones (2 members)
- Space (1 member)
- Spam (3 members)
- Standards (3 members)
- Stub (2 members)
- Stubs (0 members)
- Study Guides (13 members)
- Subgenius (1 member)
- Sufism (1 member)
- Suizid (1 member)
- Sun Hardware (1 member)
- Surveillance (2 members)
- Survival (24 members)
- Sustainable (13 members)
- Symbols (2 members)
- Syndication (1 member)
- TCL (10 members)
- TV (2 members)
- Tablatures (1 member)
- Template:Lizenz für Bilder (0 members)
- Templates (6 members)
- Timothy Leary (13 members)
- Ting (106 members)
- Tips (1 member)
- ToDo (1 member)
- Trading (1 member)
- Travel (1 member)
- Twitter (1 member)
- UFO (3 members)
- UNIX (27 members)
- USA (5 members)
- Under Construction (103 members)
- Units (1 member)
- Unix (52 members)
- Urban Legends (6 members)
- UseMod (3 members)
- VRML (3 members)
- Veritas (1 member)
- Voice (11 members)
- Vollmondtage (13 members)
- VxVM (1 member)
- Wallpapers (1 member)
- Web (3 members)
- Webdesign ? (1 member)
- Websites (132 members)
- Wiki (237 members)
- WikiCulture (1 member)
- Wiki Calendar (2 members)
- Wiki hives (9 members)
- Wikilandia (6 members)
- Wikimania (2 members)
- Wikimedia Commons (14 members)
- Wikimedia Projects (16 members)
- Wikipedia Asyl (1 member)
- Wikistats (41 members)
- Window Managers (6 members)
- Windows (76 members)
- Windows processes (2 members)
- Women (5 members)
- X3D (2 members)
- Yoga (81 members)