Blackdown Java
Encyclopedia
Blackdown Java was a Linux
port
of Sun Microsystems
's Java virtual machine
, developed by a group of volunteers led by Karl Asha and Juergen Kreileder. It predated Sun's official Linux port, and supported Linux on architectures
that the official version did not, including SPARC
and PowerPC
. The Blackdown project ended in August 2007, after Sun released an open source version of the HotSpot
JVM as part of OpenJDK; OpenJDK is available under the free GNU General Public License
. The Java software itself still exists on many mirrors.
At its close, Blackdown supported J2SE versions 1.4.2 on i386 and AMD64, 1.4.1 on SPARC, and 1.3.1 on PowerPC Work on J2SE 1.5.x support for x86, AMD64, SPARC, and PowerPC had been announced, but was never released.
In 1999 Sun Microsystems and Inprise announced a port of Java to Linux. The port was based on Blackdown work, but the Blackdown team was not recognized or given any credit for the release. After some controversy, Sun publicly apologized to the Blackdown developers. The incident revealed that there were long standing problems between Sun and Blackdown.
Despite widespread confusion, Blackdown was neither free software
nor open-source software
. Its binary redistribution policy allowed it to be pre-installed or included with many Linux distributions (e.g., Gentoo Linux
), whereas at the time, Sun Java's binary redistribution policy did not. Since Java 5, the Operating System Distributor License for Java (DLJ) met many Linux distributions' requirements, lessening the demand for the older Blackdown JVM.
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
port
Porting
In computer science, porting is the process of adapting software so that an executable program can be created for a computing environment that is different from the one for which it was originally designed...
of Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...
's Java virtual machine
Java Virtual Machine
A Java virtual machine is a virtual machine capable of executing Java bytecode. It is the code execution component of the Java software platform. Sun Microsystems stated that there are over 4.5 billion JVM-enabled devices.-Overview:...
, developed by a group of volunteers led by Karl Asha and Juergen Kreileder. It predated Sun's official Linux port, and supported Linux on architectures
Instruction set
An instruction set, or instruction set architecture , is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O...
that the official version did not, including SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
and PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
. The Blackdown project ended in August 2007, after Sun released an open source version of the HotSpot
HotSpot
HotSpot is a Java virtual machine for desktops and servers, maintained and distributed by Oracle Corporation. It features techniques such as just-in-time compilation and adaptive optimization designed to improve performance.-History:...
JVM as part of OpenJDK; OpenJDK is available under the free GNU General Public License
GNU General Public License
The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....
. The Java software itself still exists on many mirrors.
At its close, Blackdown supported J2SE versions 1.4.2 on i386 and AMD64, 1.4.1 on SPARC, and 1.3.1 on PowerPC Work on J2SE 1.5.x support for x86, AMD64, SPARC, and PowerPC had been announced, but was never released.
In 1999 Sun Microsystems and Inprise announced a port of Java to Linux. The port was based on Blackdown work, but the Blackdown team was not recognized or given any credit for the release. After some controversy, Sun publicly apologized to the Blackdown developers. The incident revealed that there were long standing problems between Sun and Blackdown.
Despite widespread confusion, Blackdown was neither free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
nor open-source software
Open-source software
Open-source software is computer software that is available in source code form: the source code and certain other rights normally reserved for copyright holders are provided under a software license that permits users to study, change, improve and at times also to distribute the software.Open...
. Its binary redistribution policy allowed it to be pre-installed or included with many Linux distributions (e.g., Gentoo Linux
Gentoo Linux
Gentoo Linux is a computer operating system built on top of the Linux kernel and based on the Portage package management system. It is distributed as free and open source software. Unlike a conventional software distribution, the user compiles the source code locally according to their chosen...
), whereas at the time, Sun Java's binary redistribution policy did not. Since Java 5, the Operating System Distributor License for Java (DLJ) met many Linux distributions' requirements, lessening the demand for the older Blackdown JVM.
External links
- jdk-distros: community collaboration with the DLJ - The official site for the DLJ.