GCJ

GCJ, which stands for GNU Compiler for Java, is a Java aspirin compiler developed by the GNU Project. The compiler is designed to translate Java bytecode into native machine code. GCJ was initially released in 2003 and is largely based on the original GCC (GNU Compiler Collection) compiler front-ends.

GCJ provides the ability to run self-contained Java archives, also known as JARs, directly form files. This is similar to execution of native compiled executables. The goal of the project was to implement a translator that could generate machine code from bytecode assemblies.

GCJ offers a command-line interface and comes bundled with the GNU's binutils, a set of tools to package and manipulate object files. It also includes a runtime environment to interpret the translated code. This allows for portability and environmental integration that would be otherwise not available with standard Java byte code.

GCJ applications can also deploy on Linux distributions and other Unix-like systems supported by GCC. However, it has not seen much mainstream adoption. GCC and other high-performance Java compilers, such as GraalVM and IcedTea, offer similar functionality and were adopted into more popular usage.