Apache Commons Lang, a package of Java utility classes for the classes that are in java.lang's hierarchy, or are considered to be so standard as to justify existence in java.lang.

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Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more.

The Apache Commons IO library contains utility classes, stream implementations, file filters, file comparators, endian transformation classes, and much more.

JSON is a light-weight, language independent, data interchange format. See http://www.JSON.org/ The files in this package implement JSON encoders/decoders in Java.

GuicedEE Inject is an open-source Guice integration library that discovers binders/modules across JARs via SPI and classpath scanning, bootstraps logging, job services, and JRT URL handling, and keeps optional adapters (e.g., Vert.x) isolated. ...

Javassist (JAVA programming ASSISTant) makes Java bytecode manipulation simple. It is a class library for editing bytecodes in Java.

Guice is a lightweight dependency injection framework for Java 11 and above

Jakarta Expression Language provides a specification document, API, reference implementation and TCK that describes an expression language for Java applications.

The Apache Commons Collections package contains types that extend and augment the Java Collections Framework.