Open Divergence Radar Catalog Method Feedback

Is zlib-ng/zlib-ng the fork of madler/zlib?

zlib-ng/zlib-ng subject · fork candidate fork of? madler/zlib object · upstream base

zlibng-zlib · status observed

Data verified at: 2026-09-11T16:52:53Z (UTC)

Conclusion status

No confirmed conclusion exists for this pair. The evidence below is presented for transparency; a relationship conclusion requires a human review that has not happened, or a previous decision no longer matches the current evidence.

No directional succession or fork claim was found; the current evidence does not establish the researched relationship.

Seed context: Research question: is zlib-ng a fork/replacement of zlib, and does it claim succession?

Observed repository facts

As of the last verified collection. These are facts about the snapshots, not activity verdicts — a low number is not a claim that a project is inactive.

EndpointRepoStarsLast pushForkArchived
zlib-ng/zlib-ng zlib-ng/zlib-ng 2090 2026-09-06T05:44:55Z no no
madler/zlib madler/zlib 7076 2026-06-01T09:13:57Z no no

Versions & deployment facts

Official release and package declarations, compared independently of the relationship verdict. These are not installation tests or a migration guarantee. Missing declarations mean unknown.

zlib-ng/zlib-ng

GitHub release · 2.3.3

Official source

GitHub latest published non-prerelease (not a semantic-version ranking). Verified: 2026-09-16T11:13:53.818Z (UTC).

Listed release assets only. Asset names do not prove platform support or successful execution.

Runtime declarations
Not declared / unknown
Operating systems
Not declared / unknown
CPU architectures
Not declared / unknown
C libraries
Not declared / unknown
Direct dependency declarations
Not declared / unknown
Published artifacts (6)
Provenance

Parser: software-1

First observed: 2026-09-16T11:13:53.818Z (UTC)

Last checked: 2026-09-16T11:13:53.818Z (UTC)

Source response SHA-256: cfe6897d6e2d44ec69b458719d90fcbb7fb1f48756d7d74dbe340bd994a4d298

madler/zlib

GitHub release · v1.3.2

Official source

GitHub latest published non-prerelease (not a semantic-version ranking). Verified: 2026-09-16T11:13:53.818Z (UTC).

Listed release assets only. Asset names do not prove platform support or successful execution.

Runtime declarations
Not declared / unknown
Operating systems
Not declared / unknown
CPU architectures
Not declared / unknown
C libraries
Not declared / unknown
Direct dependency declarations
Not declared / unknown
Published artifacts (6)
Provenance

Parser: software-1

First observed: 2026-09-16T11:13:53.818Z (UTC)

Last checked: 2026-09-16T11:13:53.818Z (UTC)

Source response SHA-256: 0e11c2b4915226969a48244c3d17944b2535340d57b21c9cdb9b50a839bcddd3

Timeline

“Event time” is an upstream timestamp when the source provides one; “first observed” is when this project saw it. They are deliberately separate columns.

EventEvent timeFirst observedSource
zlib-ng/zlib-ng metadata first observed 2026-09-11T16:52:49Z link
recent commit activity of zlib-ng/zlib-ng observed (5 commits in sampled window) 2026-05-19T20:49:31Z 2026-09-11T16:52:52Z link
madler/zlib metadata first observed 2026-09-11T16:52:53Z link
recent commit activity of madler/zlib observed (5 commits in sampled window) 2026-04-05T22:14:04Z 2026-09-11T16:52:55Z link
automatic evaluation -> insufficient_data 2026-09-11T16:53:25Z
automatic evaluation -> insufficient_data 2026-09-11T16:58:20Z
automatic evaluation -> insufficient_data 2026-09-12T02:55:35Z
automatic evaluation -> insufficient_data 2026-09-12T02:57:05Z
automatic evaluation -> insufficient_data 2026-09-12T02:59:28Z

Decision and dispute history

Review decisions are recorded privately with reasons that stay internal; this public history shows what happened and when, not why.

KindWhen (UTC)
automatic evaluation → insufficient_data2026-09-11T16:53:25Z
automatic evaluation → insufficient_data2026-09-11T16:58:20Z
automatic evaluation → insufficient_data2026-09-12T02:55:35Z
automatic evaluation → insufficient_data2026-09-12T02:57:05Z
automatic evaluation → insufficient_data2026-09-12T02:59:28Z

To question this report, use the feedback form, select “data error”, and include pair ID zlibng-zlib. Feedback is reviewed privately and does not change a report automatically.

Snapshot taken at 2026-09-16T13:11:39.533Z (UTC).