| Original author(s) | Sun Microsystems |
|---|---|
| Developer(s) | Oracle Corporation |
| Written in | C |
| Type | Java virtual machine |
| Website | www |
The K virtual machine (KVM) is a virtual machine developed by Sun Microsystems (now owned by Oracle Corporation), derived from the Java virtual machine (JVM) specification. The KVM was written from scratch in the programming language C. It is designed for small devices with 128K to 256K of available computer memory, and minimizes memory use. It supports a subset of the features of the higher end JVM. For example, a KVM may not support floating-point arithmetic and object finalization. The Connected Limited Device Configuration (CLDC) specifies use of the KVM. The 'K' in KVM stands for kilobyte, signifying that the KVM runs in kilobytes of memory in contrast to megabytes. [1]
Java is a general-purpose programming language that is class-based, object-oriented, and designed to have as few implementation dependencies as possible. It is intended to let application developers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but it has fewer low-level facilities than either of them. As of 2019, Java was one of the most popular programming languages in use according to GitHub, particularly for client-server web applications, with a reported 9 million developers.
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.
Java Platform, Micro Edition or Java ME is a computing platform for development and deployment of portable code for embedded and mobile devices. Java ME was formerly known as Java 2 Platform, Micro Edition or J2ME.
A MIDlet is an application that uses the Mobile Information Device Profile (MIDP) of the Connected Limited Device Configuration (CLDC) for the Java ME environment. Typical applications include games running on mobile devices and cell phones which have small graphical displays, simple numeric keypad interfaces and limited network access over HTTP. MIDlet can run on Android devices via the J2ME Loader emulator application.
Rhino is a JavaScript engine written fully in Java and managed by the Mozilla Foundation as open source software. It is separate from the SpiderMonkey engine, which is also developed by Mozilla, but written in C++ and used in Mozilla Firefox.
The system console, computer console, root console, operator's console, or simply console is the text entry and display device for system administration messages, particularly those from the BIOS or boot loader, the kernel, from the init system and from the system logger. It is a physical device consisting of a keyboard and a screen, and traditionally is a text terminal, but may also be a graphical terminal. System consoles are generalized to computer terminals, which are abstracted respectively by virtual consoles and terminal emulators. Today communication with system consoles is generally done abstractly, via the standard streams, but there may be system-specific interfaces, for example those used by the system kernel.
The Connected Limited Device Configuration (CLDC) is a specification of a framework for Java ME applications describing the basic set of libraries and virtual-machine features that must be present in an implementation. The CLDC is combined with one or more profiles to give developers a platform for building applications on embedded devices with very limited resources such as pagers and mobile phones. The CLDC was developed under the Java Community Process as JSR 30 and JSR 139.
Write once, run anywhere (WORA), or sometimes Write once, run everywhere (WORE), was a 1995 slogan created by Sun Microsystems to illustrate the cross-platform benefits of the Java language. Ideally, this meant that a Java program could be developed on any device, compiled into standard bytecode, and be expected to run on any device equipped with a Java virtual machine (JVM). The installation of a JVM or Java interpreter on chips, devices, or software packages became an industry standard practice.
HotSpot, released as Java HotSpot Performance Engine, is a Java virtual machine for desktop and server computers, maintained and distributed by Oracle Corporation. It features improved performance via methods such as just-in-time compilation and adaptive optimization.
Jazelle DBX is an extension that allows some ARM processors to execute Java bytecode in hardware as a third execution state alongside the existing ARM and Thumb modes. Jazelle functionality was specified in the ARMv5TEJ architecture and the first processor with Jazelle technology was the ARM926EJ-S. Jazelle is denoted by a "J" appended to the CPU name, except for post-v5 cores where it is required for architecture conformance.
The Sun Java Wireless Toolkit is a toolbox for developing wireless applications that are based on JavaME's Connected Limited Device Configuration (CLDC) and Mobile Information Device Profile (MIDP), and designed to run on cell phones, personal digital assistants, and other small mobile devices. The toolkit includes the emulation environments, performance optimization and tuning features, documentation, and examples.
Java is a set of computer software and specifications developed by James Gosling at Sun Microsystems, which was later acquired by the Oracle Corporation, that provides a system for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages.
In software development, the programming language Java was historically considered slower than the fastest 3rd generation typed languages such as C and C++. The main reason being a different language design, where after compiling, Java programs run on a Java virtual machine (JVM) rather than directly on the computer's processor as native code, as do C and C++ programs. Performance was a matter of concern because much business software has been written in Java after the language quickly became popular in the late 1990s and early 2000s.
Memory footprint refers to the amount of main memory that a program uses or references while running.
The phoneME project is Sun Microsystems reference implementation of Java virtual machine and associated libraries of Java ME with source, licensed under the GNU General Public License.
The Microsoft Java Virtual Machine (MSJVM) is a discontinued proprietary Java virtual machine from Microsoft. It was first made available for Internet Explorer 3 so that users could run Java applets when browsing on the World Wide Web. It was the fastest Windows-based implementation of a Java virtual machine for the first two years after its release. Sun Microsystems, the creator of Java, sued Microsoft in October 1997 for incompletely implementing the Java 1.1 standard. It was also named in the United States v. Microsoft Corp. antitrust civil actions, as an implementation of Microsoft's "Embrace, extend and extinguish" strategy. In 2001, Microsoft settled the lawsuit with Sun and discontinued its Java implementation.
The Da Vinci Machine, also called the Multi Language Virtual Machine, was a Sun Microsystems project aiming to prototype the extension of the Java Virtual Machine (JVM) to add support for dynamic languages.
Mika VM is an open-source implementation of the Java virtual machine specification, together with class libraries which implement the Connected Device Configuration of Java ME. Mika VM is based on Wonka VM, which was developed independently of any other implementation, including Sun Microsystem's RI. The same is true of most of the class libraries, but in this case some code is drawn from the GNU Classpath and Apache Harmony projects. MikaVM support MIDP 1.0 and 2.0, CDC Personal Profile.
TakaTuka is a Java virtual machine (JVM) mainly focused on wireless sensor network devices. The VM focussed on supporting small devices with at least 4 KiB of RAM and greater than 48 KiB of flash memory. TakaTuka currently offers CLDC compatible library support.
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