The Tascalate Concurrent library provides an implementation of the CompletionStage interface and related classes. These are designed to support long-running blocking tasks (typically, I/O bound). This functionality augments the sole Java 8 built-in implementation, CompletableFuture, that primarily supports computational tasks. Also, the library helps with numerous asynchronous programming challenges like handling timeouts, retry/poll functionality, orchestrating results of multiple concurrent computations, and similar.
The library is shipped as a multi-release JAR and may be used both with Java 8 as a classpath library or with Java 9+ as a module.