The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Repositories (1 member)
- Requirements (1 member)
- Requirements analysis (1 member)
- Resurgence Magazine (1 member)
- Reticulation (1 member)
- Reuse (1 member)
- Reviews (1 member)
- Revision control (1 member)
- Revolution (1 member)
- Richard Flanagan (1 member)
- Richard Stallman (1 member)
- Right Ordering (2 members)
- Ripping (1 member)
- Robert Macfarlane (1 member)
- Roel Loopers (1 member)
- Roots (1 member)
- Rosie O'Gradys (2 members)
- Rotation (1 member)
- Roundhouse (1 member)
- Routing (1 member)
- Rowan Atkinson (1 member)
- Rsync (1 member)
- Rsync.net (0 members)
- SFTP (1 member)
- SGI 1600SW (1 member)
- SQL (4 members)
- STV (1 member)
- San Francisco (1 member)
- Satish Kumar (1 member)
- Saving (1 member)
- Saw horses (1 member)
- Saw stools (1 member)
- Sawdust (1 member)
- Sawing (3 members)
- Scanning (1 member)
- Scenery (1 member)
- Scheduling (1 member)
- Schema (1 member)
- Scotland (2 members)
- Scott Hanselman (1 member)
- Scripts (3 members)
- Searching (1 member)
- Selecting (1 member)
- SemanticForms (2 members)
- SemanticMediaWiki (1 member)
- Semantic MediaWiki (6 members)
- Semantic web (1 member)
- Sessions (1 member)
- Sewing (1 member)
- Sharpening (1 member)