Repository brief

ReactiveX/RxJava

Read the upstream summary on the left, browse the cached forks below it, and load each fork comparison into the right-hand panel.

Cached analysis

cached 2026-03-30T11:46:26.774Z

ReactiveX/RxJava

RxJava is a large, active JVM library for composing asynchronous and event-based programs with observable sequences. The repo is the 4.x line, recently updated on 2026-03-30, and appears highly mature and widely adopted, with 48,449 stars and 7,601 forks.

GitHub

Stars48,449

Forks7,601

Default branch4.x

Last pushed2026-03-30T07:28:23Z

Best maintainedNone

Closest to upstreamakarnokd/RxJava

Most feature-richbenjchristensen/RxJava

Most opinionatedbenjchristensen/RxJava

Forks

Choose a fork to inspect

9 cached fork briefs

Fork comparison

lungerWang/RxJava

stale

significant_divergence

Choose this fork only if you need legacy RxJava 1.x compatibility and are willing to own a stale, highly diverged codebase. If you want active maintenance, modern JVM support, or upstream alignment, the main RxJava line is the better fit.

Likely purpose

To preserve or customize the older RxJava 1.x line for users who need that API, rather than track upstream 4.x.

Best for

Teams maintaining an older application already built on RxJava 1.x.; Developers who need a frozen fork to patch legacy behavior without migrating APIs.; Organizations that value compatibility with historical `rx.*` code over access to current upstream features.

Additional features

Keeps a separate 1.x codebase with its own `rx.*` sources and tests, which suits projects still bound to the legacy API.
Contains substantial local test and documentation history around 1.x behavior, suggesting a fork used for maintaining or patching the older branch.
May be useful as a frozen compatibility base for legacy JVM projects that cannot migrate to `io.reactivex.rxjava4`.
Changes agent workflow behavior, such as prompt handling, handoffs, worktrees, memory, or orchestration flow.

Missing features

Does not track upstream 4.x features such as Java 26 baseline support, `io.reactivex.rxjava4` namespaces, Flow-based implementation, or virtual thread support.
Appears far behind upstream in time, with the last push in 2016 versus active upstream maintenance in 2026.
Large deletion-heavy divergence suggests many newer upstream operators, fixes, build changes, and docs are absent or harder to use here.
Some upstream behavior appears to be removed, disabled, or intentionally stripped down in this fork.
It trails upstream by 201 commits, so some recent upstream features and fixes are likely not present yet.

Strengths

Legacy RxJava 1.x API compatibility.
Very large code delta implies it is not just a thin wrapper, but a self-contained fork.
Could be easier to adopt for an existing codebase already locked to `rx.*` types.

Risks

Severe upstream drift makes bug fixes and security updates harder to inherit.
High maintenance burden because the fork is stale and far behind current RxJava architecture.
Adopters may face migration friction later because the fork is not aligned with the modern 4.x line.