.alg
2 claimants
2 primary
0 secondary
shared primary (2)
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.
200.7K
total files
147.0K
first seen 2021–2025 (73.2%)
2022
median year (half its files since)
Case variants in archive: .ALG (120.4K), .alg (80.3K), .Alg (19) — aggregated above.
Attribution status
This extension is attributed to ALGOL; Portugol as primary by 3 authoritative claims.
Claimants (3)
Languages that list
.alg among their extensions. Strength reflects whether the upstream source treated it as their primary extension.| Language | Source | Strength |
|---|---|---|
| ALGOL | linguist | primary |
| ALGOL | pygments | primary |
| Portugol | pygments | primary |
Wikidata says… (2)
File formats, image formats, audio codecs and other non-PL
entities that claim
.alg 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 |
|---|---|---|---|---|---|
| AlgoBox Algorithm Q105853773 file format | file format | — | text/plain | — | Use as new PL ↗ |
| Portugol file format Q130485173 file format | file format | — | — | — | Use as new PL ↗ |
Disambiguation rules (1)
Linguist heuristics that decide, by content, which language a
.alg file actually is.| Rule | Predicts | Kind | Predicates (truncated) | Measured on SWH |
|---|---|---|---|---|
h/linguist/.alg/0 | ALGOL | predicates | [{"kind": "any", "regexes": ["(?i)^comment\\b.*(;|comment)", "^#[^#\\r\\n]+#$", "(?i)\\b(integer|real|boolean|string)\\b\\s+\\w+\\s*:=\\s*", "(?i)^begin[\\s\\S]*^end"]}] |
SWH-mined examples (0)
No archived examples for .alg in our local mirror yet.