Base reactive classes:Flowable,Observable,Single,Maybe andCompletable; base reactive consumers; other common base interfaces.

Annotations for indicating experimental and beta operators, classes, methods, types or fields.

Default implementations for Disposable-based resource management (Disposable container types) and utility classes to construct Disposables from callbacks and other types.

Exception handling utilities, safe subscriber exception classes, lifecycle exception classes.

Classes supporting the Flowable base reactive class:ConnectableFlowable andGroupedFlowable.

Functional interfaces of functions and actions of arity 0 to 9 and related utility classes.

Classes supporting the Observable base reactive class:ConnectableObservable andGroupedObservable.

Default wrappers and implementations for Observer-based consumer classes and interfaces, including disposable and resource-tracking variants and theTestObserver that allows unit testingObservable-,Single-,Maybe- andCompletable-based flows.

Contains the base typeParallelFlowable, a sub-DSL for working withFlowable sequences in parallel.

Contains the central plugin handlerRxJavaPlugins class to hook into the lifecycle of the base reactive types and schedulers.

Classes representing so-called hot backpressure-aware sources, akaprocessors, that implement theFlowableProcessor class, the Reactive StreamsProcessor interface to allow forms of multicasting events to one or more subscribers as well as consuming another Reactive StreamsPublisher.

Contains notably the factory class ofSchedulers providing methods for retrieving the standard scheduler instances, theTestScheduler for testing flows with scheduling in a controlled manner and the classTimed that can hold a value and a timestamp associated with it.

Classes representing so-called hot sources, aka subjects, that implement a base reactive class and the respective consumer type at once to allow forms of multicasting events to multiple consumers as well as consuming another base reactive type of their kind.

Default wrappers and implementations for Subscriber-based consumer classes and interfaces, including disposable and resource-tracking variants and theTestSubscriber that allows unit testingFlowable-based flows.