The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Shimano (1 member)
- Shipping (3 members)
- Ships (1 member)
- Silas Marner (1 member)
- Silence (1 member)
- Simplicity (1 member)
- Skinning (1 member)
- Slate (2 members)
- Slideshows (1 member)
- Slowing down (2 members)
- Snopes (1 member)
- Social media (1 member)
- Social networking (10 members)
- Societies (2 members)
- Soetsu Yanagi (1 member)
- Software (16 members)
- Software engineering (1 member)
- Sol-R (1 member)
- Sorting (2 members)
- Sources (1 member)
- South Beach (1 member)
- Soylent (1 member)
- Spain (2 members)
- Spearwood (1 member)
- Speed (8 members)
- Speed of response (2 members)
- Spivak pronouns (1 member)
- Squirrelmail (2 members)
- St Johns Church (2 members)
- Stack Overflow (2 members)
- Static web pages (1 member)
- Stations (2 members)
- Status updates (36 members)
- Stones (1 member)
- Stonewaves (1 member)
- Storage (8 members)
- Stories (2 members)
- Strings (1 member)
- Suburbia (2 members)
- Subversion (4 members)
- Surveillance (1 member)
- Surveys (4 members)
- Susan Cain (1 member)
- Category:Subversion (0 members)
- Swan River (1 member)
- Syncing (1 member)
- Syncronization (3 members)
- System administration (7 members)
- Systems (1 member)
- Systen administration (2 members)