Code · ukparliament · UK Public Sector GitHub Observatory

Language figures come from GitHub's own per-repository byte counts, which measure source rather than a single headline label. File counts and repository sizes come from the mirrors themselves. The two tell different stories, and the difference is the point.

The codebase

languages in use

70.8 MB of source

38.9k

files at HEAD

across every analysed repository

0 B

on disk as mirrors

full history, every branch and tag

2.0 GB

largest repository

ontologies

What stands out

One archived repository holds 50% of all the bytes.

ontologies is 2.0 GB of git - a 2013 static snapshot of www.gov.uk, not source code. It single-handedly makes HTML the largest language by volume (50% of all source bytes). Any size or language statistic that does not exclude it is measuring an archive, not a codebase.

Sizes here are GitHub's reported figures.

This organisation was harvested with blobless partial clones, which fetch every commit and file path but not file contents, so there is no local size to measure against. Checked elsewhere in this dataset against 1,526 fully mirrored repositories, GitHub's reported size is accurate to within about six percent.

Ruby is the house language, but its share is falling.

Ruby is the primary language of 33% of archived repositories but only 31% of live ones. Python, Go, TypeScript and HCL have taken the difference - the signature of a shift from monolithic Rails publishing apps toward data pipelines, infrastructure-as-code and platform tooling.

Most repositories are small; a handful are enormous.

65% of repositories are under a megabyte of git data. The estate is not a monolith - it is a very long tail of small services, gems and prototypes around a few large publishing applications.

Languages, two ways

By volume of source

Bytes of code. Dominated by archived static HTML.

By number of repositories

How many repositories name each language as their primary one. A better guide to what engineers actually work in.

Live estate versus archive

The same language ranking, split by whether the repository is still active. The shift is the clearest signal of technical direction in the whole dataset.

Active repositories

Archived repositories

Scale

Repository size distribution

Git data per repository, log-ish buckets.

Commits against files

Each circle is a repository, sized by number of distinct authors. Both axes are logarithmic. The diagonal band is the normal relationship between codebase size and churn; outliers above it are long-lived apps with heavy iteration, below it are dumps and imports.

The shape of a repository

Directory layout is the cheapest reliable signal of what a repository actually is. app/ with config/ and spec/ is a Rails application; src/ with test/ is Java or Node. Counted by how many repositories contain each top-level directory at HEAD.

Most common top-level directories

Most common file extensions

By total file count across the estate.

The twenty largest repositories

Repository	Language	Git size	Commits	Files	Status
ontologies	HTML	2.0 GB	20,480	1,187	active
armada.parliament.uk	HTML	813.7 MB	43	966	active
mp-for-a-week	JavaScript	279.8 MB	12	4,174	active
my-constituency-app	JavaScript	225.5 MB	11	2,003	active
uk-treaties	Ruby	155.2 MB	338	12,645	archived
standing-orders	JavaScript	61.9 MB	501	284	active
parliament.uk-prototype	Ruby	37.9 MB	1,776	815	active
Orchestration	C#	31.0 MB	461	434	active
psephology	HTML	30.5 MB	3,755	836	active
uk.parliament-visual	JavaScript	27.9 MB	272	151	active
parliament.uk-outputs-prototypes	HTML	19.2 MB	9	79	archived
parliament.uk-lists	Ruby	19.2 MB	493	1,056	active
peerages	JavaScript	19.0 MB	683	385	active
Procedures	CSS	18.9 MB	123	67	active
Procedure	CSS	18.9 MB	109	60	active
domain-models	-	17.9 MB	97	106	active
egg-timer	HTML	17.2 MB	2,960	360	active
pugin-components	JavaScript	15.4 MB	260	295	active
visual.parliament.uk-msoanames	CSS	15.2 MB	168	86	active
procedure-parsing	JavaScript	12.6 MB	1,048	249	active