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Kaffe
Kaffe is a discontinued "clean room design" (reverse engineering) version of a Java Virtual Machine. It comes with a subset of the Java Platform, Standard Edition (Java SE), Java API, and tools needed to provide a Java runtime environment. Like most other Free Java virtual machines, Kaffe uses GNU Classpath as its class library. Kaffe, first released in 1996, was the original open-source Java implementation. Initially developed as part of another project, it grew so popular that developers Tim Wilkinson and Peter Mehlitz founded Transvirtual Technologies, Inc. with Kaffe as the company's flagship product. In July 1998, Transvirtual released Kaffe OpenVM under a GNU General Public License. Kaffe is a lean and portable virtual machine, although it is significantly slower than commercial implementations. When compared to the reference implementation of the Java Virtual Machine written by Sun Microsystems, Kaffe is significantly smaller; it thus appeals to embedded system developer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Classpath
GNU Classpath is a free software implementation of the standard class library for the Java programming language. Most classes from J2SE 1.4 and 5.0 are implemented. Classpath can thus be used to run Java-based applications. GNU Classpath is a part of the GNU Project. It was originally developed in parallel with libgcj due to license incompatibilities, but later the two projects merged. GNU Classpath was deemed a high priority project by the Free Software Foundation. When the Classpath project began, the license for the official Java implementation from Sun Microsystems did not allow distribution of any alterations. Since the inception of the Classpath project, the OpenJDK was released under the GPL and now serves as the official reference implementation for the Java platform. License GNU Classpath is licensed under the GNU General Public License with a linking exception. This is a free software license. All code is formally owned by the Free Software Foundation, and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Java Implementations
Free Java implementations are software projects that implement Oracle's Java technologies and are distributed under free software licences, making them free software. Sun released most of its Java source code as free software in May 2007, so it can now almost be considered a free Java implementation. Java implementations include compilers, runtimes, class libraries, etc. Advocates of free and open source software refer to free or open source Java virtual machine software as free runtimes or free Java runtimes. Some advocates in this movement prefer not to use the term "Java" as it has trademark issues associated with it. Hence, even though it is a "free Java movement", the term "free Java runtimes" is avoided by them. Mid-1990s to 2006 The first free project to offer substantial parts of Java platform functionality was likely guavac, which began some time before November 1995. Since then, the free software movement developed other Java compilers, most notably the GNU Compiler for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Java Virtual Machines
This article provides non-exhaustive lists of Java SE Java virtual machines (JVMs). It does not include every Java ME vendor. Note that Java EE runs on the standard Java SE JVM but that some vendors specialize in providing a modified JVM optimized for Java EE applications. Much Java development work takes place on Windows, Solaris, Linux, and FreeBSD, primarily with the Oracle JVMs. Note the further complication of different 32-bit/64-bit varieties. The primary reference Java VM implementation is HotSpot, produced by Oracle Corporation and many other big and medium-sized companies (e.g. IBM, Redhat, Microsoft, Azul, SAP). Free and open source implementations Active * Codename One – uses the open source ParparVM * Eclipse OpenJ9 – open-source from IBM J9, for AIX, Linux (x86, Power, and Z), macOS, Windows, MVS, OS/400, Pocket PC, z/OS. * GraalVM – is based on HotSpot/OpenJDK, it has a polyglot feature, to transparently mix and match supported languages. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Multi-Precision Library
GNU Multiple Precision Arithmetic Library (GMP) is a free library for arbitrary-precision arithmetic, operating on signed integers, rational numbers, and floating-point numbers. There are no practical limits to the precision except the ones implied by the available memory (operands may be of up to 232−1 bits on 32-bit machines and 237 bits on 64-bit machines). GMP has a rich set of functions, and the functions have a regular interface. The basic interface is for C, but wrappers exist for other languages, including Ada, C++, C#, Julia, .NET, OCaml, Perl, PHP, Python, R, Ruby, and Rust. Prior to 2008, Kaffe, a Java virtual machine, used GMP to support Java built-in arbitrary precision arithmetic. Shortly after, GMP support was added to GNU Classpath. The main target applications of GMP are cryptography applications and research, Internet security applications, and computer algebra systems. GMP aims to be faster than any other bignum library for all operand sizes. Some impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Class Library
The Java Class Library (JCL) is a set of dynamically loadable libraries that Java Virtual Machine (JVM) languages can call at run time. Because the Java Platform is not dependent on a specific operating system, applications cannot rely on any of the platform-native libraries. Instead, the Java Platform provides a comprehensive set of standard class libraries, containing the functions common to modern operating systems. JCL serves three purposes within the JVM: * Like other standard code libraries, they provide the programmer a well-known set of useful facilities, such as container classes and regular expression processing. * The library provides an abstract interface to tasks that would normally depend heavily on the hardware and operating system, such as network access and file access. * Some underlying platforms may not support all of the features a Java application expects. In these cases, the library implementation can either emulate those features or provide a consistent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-like application is one that behaves like the corresponding Unix command or shell. Although there are general philosophies for Unix design, there is no technical standard defining the term, and opinions can differ about the degree to which a particular operating system or application is Unix-like. Some well-known examples of Unix-like operating systems include Linux and BSD. These systems are often used on servers, as well as on personal computers and other devices. Many popular applications, such as the Apache web server and the Bash shell, are also designed to be used on Unix-like systems. One of the key features of Unix-like systems is their ability to support multiple users and processes simultaneously. This allows users to run multipl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Just-in-time Compilation
In computing, just-in-time (JIT) compilation (also dynamic translation or run-time compilations) is a way of executing computer code that involves compilation during execution of a program (at run time) rather than before execution. This may consist of source code translation but is more commonly bytecode translation to machine code, which is then executed directly. A system implementing a JIT compiler typically continuously analyses the code being executed and identifies parts of the code where the speedup gained from compilation or recompilation would outweigh the overhead of compiling that code. JIT compilation is a combination of the two traditional approaches to translation to machine code—ahead-of-time compilation (AOT), and interpretation—and combines some advantages and drawbacks of both. Roughly, JIT compilation combines the speed of compiled code with the flexibility of interpretation, with the overhead of an interpreter and the additional overhead of compil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenJDK
OpenJDK (Open Java Development Kit) is a free and open-source implementation of the Java Platform, Standard Edition (Java SE). It is the result of an effort Sun Microsystems began in 2006. The implementation is licensed under the GPL-2.0-only with a linking exception. Were it not for the GPL linking exception, components that linked to the Java class library would be subject to the terms of the GPL license. OpenJDK is the official reference implementation of Java SE since version 7. Components The OpenJDK project produces a number of components: most importantly the virtual machine ( HotSpot), the Java Class Library and the Java compiler (javac). The web-browser plugin and Web Start, which form part of Oracle Java, are not included in OpenJDK. Sun previously indicated that they would try to open-source these components, but neither Sun nor Oracle have done so. The only currently available free plugin and Web Start implementations are those provided by IcedTea. OpenJDK 9+ su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PlayStation 2
The PlayStation 2 (PS2) is a home video game console developed and marketed by Sony Computer Entertainment. It was first released in Japan on 4 March 2000, in North America on 26 October 2000, in Europe on 24 November 2000, and in Australia on 30 November 2000. It is the successor to the original PlayStation (console), PlayStation, as well as the second installment in the PlayStation brand of consoles. As a sixth generation of video game consoles, sixth-generation console, it competed with Nintendo's GameCube, and Microsoft's Xbox (console), Xbox. It is the List of best-selling game consoles, best-selling video game console of all time, having sold over 155 million units worldwide. Announced in 1999, Sony began developing the console after the immense success of its predecessor. The PS2 offered Backward compatibility, backward-compatibility for its predecessor's DualShock#DualShock, DualShock controller, as well as its games. The PlayStation 2 received widespread critical accla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mainframe Computer
A mainframe computer, informally called a mainframe or big iron, is a computer used primarily by large organizations for critical applications like bulk data processing for tasks such as censuses, industry and consumer statistics, enterprise resource planning, and large-scale transaction processing. A mainframe computer is large but not as large as a supercomputer and has more processing power than some other classes of computers, such as minicomputers, servers, workstations, and personal computers. Most large-scale computer-system architectures were established in the 1960s, but they continue to evolve. Mainframe computers are often used as servers. The term ''mainframe'' was derived from the large cabinet, called a ''main frame'', that housed the central processing unit and main memory of early computers. Later, the term ''mainframe'' was used to distinguish high-end commercial computers from less powerful machines. Design Modern mainframe design is characterized less b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM ZSeries
IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers. In July 2017, with another generation of products, the official family was changed to IBM Z from IBM z Systems; the IBM Z family now includes the newest model, the IBM z16, as well as the z15, the z14, and the z13 (released under the IBM z Systems/IBM System z names), the IBM zEnterprise models (in common use the zEC12 and z196), the IBM System z10 models (in common use the z10 EC), the IBM System z9 models (in common use the z9EC) and ''IBM eServer zSeries'' models (in common use refers only to the z900 and z990 generations of mainframe). Architecture The ''zSeries,'' ''zEnterprise,'' ''System z'' and ''IBM Z'' families were named for their availability – ''z'' stands for zero downtime. The systems are built with spare components capable of hot failovers to ensure continuous operations. The IBM Z family maintains full backward compatibility. In effect, current systems are the direct, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SuperH
SuperH (or SH) is a 32-bit reduced instruction set computing (RISC) instruction set architecture (ISA) developed by Hitachi and currently produced by Renesas. It is implemented by microcontrollers and microprocessors for embedded systems. At the time of introduction, SuperH was notable for having fixed-length 16-bit instructions in spite of its 32-bit architecture. This was a novel approach; at the time, RISC processors always used an instruction size that was the same as the internal data width, typically 32 bits. Using smaller instructions had consequences: the register file was smaller and instructions were generally two-operand format. But for the market the SuperH was aimed at, this was a small price to pay for the improved memory and processor cache efficiency. Later versions of the design, starting with SH-5, included both 16- and 32-bit instructions, with the 16-bit versions mapping onto the 32-bit version inside the CPU. This allowed the machine code to continue using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
