.cs
4 claimants
3 primary
1 secondary
shared primary (3)
SWH popularity
Distinct files in the full Software Heritage archive (2026-06-04 export), dated by first appearance, following Desmazières, Di Cosmo, Lorentz (MSR 2025). Case-aggregated. citation.
485.9M
total files
218.0M
first seen 2021–2025 (44.9%)
2020
median year (half its files since)
Case variants in archive: .cs (485.8M), .CS (22.3K), .Cs (2.0K), .cS (871) — aggregated above.
Attribution status
This extension is attributed to C Sharp (programming language); C#; csharp as primary by 5 authoritative claims.
Claimants (6)
Languages that list
.cs among their extensions. Strength reflects whether the upstream source treated it as their primary extension.| Language | Source | Strength |
|---|---|---|
| C Sharp (programming language) | pygments | primary |
| C# | linguist | primary |
| C# | pygments | primary |
| C# | wikidata | primary |
| csharp | pygments | primary |
| Smalltalk | linguist | secondary |
Wikidata says… (3)
File formats, image formats, audio codecs and other non-PL
entities that claim
.cs on Wikidata
(property P1195) or in the Wikipedia infobox.
Source: data/derived/external_extension_index.csv.
Click Use as new PL on any row to open the
Add-PL form pre-filled with that entry's name, Wikipedia/Wikidata
URL, and this extension — one submission creates the PL + claim.
| Format | Class (Wikidata P31) | Suggested label | MIME | Notes | Action |
|---|---|---|---|---|---|
| C# source code file Q111431061 file format | file format | — | text/x-csharp | — | Use as new PL ↗ |
| ColorSchemer Studio Color Scheme Q105849756 file format | file format | — | — | — | Use as new PL ↗ |
| TorqueScript file Q128203989 file format | file format | — | — | — | Use as new PL ↗ |
Disambiguation rules (2)
Linguist heuristics that decide, by content, which language a
.cs file actually is.| Rule | Predicts | Kind | Predicates (truncated) | Measured on SWH |
|---|---|---|---|---|
h/linguist/.cs/0 | Smalltalk | predicates | [{"kind": "any", "regexes": ["![\\w\\s]+methodsFor: "]}] | |
h/linguist/.cs/1 | C# | predicates | [{"kind": "any", "regexes": ["^\\s*(using\\s+[A-Z][\\s\\w.]+;|namespace\\s*[\\w\\.]+\\s*(\\{|;)|\\/\\/)"]}] |
SWH-mined examples (0)
No archived examples for .cs in our local mirror yet.