The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Highspeed Camera (1 member)
- HowTo (2 members)
- Howto (1 member)
- IDE (2 members)
- IDF (1 member)
- IFD (6 members)
- IOS (42 members)
- IPad (33 members)
- IPhone (40 members)
- IPodTouch (30 members)
- Image Processing (2 members)
- Immersive Medien (11 members)
- Initial Beginnings (1 member)
- Interaction Design (1 member)
- Interactive (4 members)
- Interactive Gestures (1 member)
- Interactivity (1 member)
- Interaktion (32 members)
- Interface-Design (33 members)
- Interface Design (21 members)
- Interfaces (26 members)
- Internet (31 members)
- Internet of Things (1 member)
- IoT (6 members)
- JAVA (4 members)
- Jan-Peter E.R. Sonntag (1 member)
- Jan Dittrich (12 members)
- Jan Sieber (3 members)
- Jason Reizner (1 member)
- Javascript (8 members)
- Jena (2 members)
- Jens Geelhaar (10 members)
- Jesús Velázquez (8 members)
- Joatan Preis Dutra (5 members)
- Jochen Viehoff (1 member)
- Joe Davis (1 member)
- Joern Hintzer & Jakob Hüfner (1 member)
- Johannes Deich (5 members)
- Johannes Dich (6 members)
- Julian Chollet (8 members)
- Juliane Fuchs (1 member)
- Jörg Brinkmann (20 members)
- Kartographie (3 members)
- Katharina Knobel (1 member)
- Katharina Rosenberger (1 member)
- Katrin Caspar (2 members)
- Kinetik (1 member)
- Klaus Fritze (2 members)
- Klaus Herbst (1 member)
- Knitting (1 member)