query: platform cascading 
supports: Cascading is a software abstraction layer for Apache Hadoop . Cascading is used to create and execute complex data processing workflows on a Hadoop cluster using any JVM - based language ( Java , JRuby , Clojure , etc. ) , hiding the underlying complexity of MapReduce jobs . It is open source and available under the Apache License . Commercial support is available from Concurrent , Inc. Cascading was originally authored by Chris Wensel , who later founded Concurrent , Inc. Cascading is being actively developed by the community and a number of add - on modules are available . A Java virtual machine (JVM) is an abstract computing machine that enables a computer to run a Java program. There are three notions of the JVM: specification, implementation, and instance. The specification is a document that formally describes what is required of a JVM implementation. Having a single specification ensures all implementations are interoperable. A JVM implementation is a computer program that meets the requirements of the JVM specification. An instance of a JVM is an implementation running in a process that executes a computer program compiled into Java bytecode.  Jython is an implementation of the Python programming language designed to run on the Java platform. It is the successor of JPython. JRuby is an implementation of the Ruby programming language atop the Java Virtual Machine, written largely in Java. It is free software released under a three-way EPL/GPL/LGPL license. JRuby is tightly integrated with Java to allow the embedding of the interpreter into any Java application with full two-way access between the Java and the Ruby code (similar to Jython for the Python language). In computing, an abstraction layer or abstraction level is a way of hiding the implementation details of a particular set of functionality, allowing the separation of concerns to facilitate interoperability and platform independence. Software models that use layers of abstraction include the OSI 7-layer model for computer network protocols, the OpenGL graphics drawing library, and the byte stream input/output (I/O) model originated from Unix and adopted by DOS, Linux, and most other modern operating systems. Clojure (like "closure") is a dialect of the Lisp programming language created by Rich Hickey. Clojure is a general-purpose programming language with an emphasis on functional programming. It runs on the Java virtual machine, Common Language Runtime, and JavaScript engines. Like other Lisps, Clojure treats code as data and has a macro system. The current development process is community-driven, overseen by Rich Hickey as its benevolent dictator for life (BDFL). JavaScript is a high-level, dynamic, untyped, and interpreted programming language. It has been standardized in the ECMAScript language specification. Alongside HTML and CSS, JavaScript is one of the three core technologies of World Wide Web content production; the majority of websites employ it, and all modern Web browsers support it without the need for plug-ins. JavaScript is prototype-based with first-class functions, making it a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles. It has an API for working with text, arrays, dates and regular expressions, but does not include any I/O, such as networking, storage, or graphics facilities, relying for these upon the host environment in which it is embedded.
  Although there are strong outward similarities between JavaScript and Java, including language name, syntax, and respective standard libraries, the two are distinct languages and differ greatly in their design. JavaScript was influenced by programming languages such as Self and Scheme.
  JavaScript is also used in environments that are not Web-based, such as PDF documents, site-specific browsers, and desktop widgets. Newer and faster JavaScript virtual machines (VMs) and platforms built upon them have also increased the popularity of JavaScript for server-side Web applications. On the client side, developers have traditionally implemented JavaScript as an interpreted language, but more recent browsers perform just-in-time compilation. Programmers also use JavaScript in video-game development, in crafting desktop and mobile applications, and in server-side network programming with run-time environments such as Node.js.
candidates: dos java java platform java virtual machine javascript linux unix web
answer: java virtual machine