Applets

An applet is a program written in the Java programming language included in an HTML page, much in the same way an image is included in a page. When you use a Java technology-enabled browser to view a page that contains an applet, the applet's code is transferred  to your system and executed by the browser's Java Virtual Machine (JVM).


Java Plug-in software enables enterprise customers to direct applets or beans written in the Java programming language on their intranet web pages to run using Sun's Java Runtime Environment (JRE), instead of the browser's default. This enables an enterprise to deploy applets that take full advantage of the latest capabilities and features of the Java platform and be assured that they will run reliably and consistently.(15)


In computing, an applet is any small application that performs one specific task in  a larger program, (e.g.,  as a plug-in).[1][2] An applet usually is a Java applets, i.e., programs written in the Java programming language in a web page." The word Applet was first used in 1990 in PC Magazine."[3]

Provided that an applet is hosted by an operating system, it can function as any other normal software application but is small and performs small tasks. Examples of applications as applets are  Windows Notepad or Microsoft Paint. Applets are not full-featured application programs and can be extensions of software through a plug-in or mobile devices that support the applet programming model.[2]


Applets are used to provide interactive features that cannot be provided by HTML alone through mouse input or controls like buttons or check boxes and change the provided graphic content well suitable for demonstration, visualization, and teaching.  Applet collections for studying various subjects, from physics[4] to heart physiology are popular.[5] Applets are also used to create online game collections and players can compete against live opponents in real-time.

An applet can also be a text area only, providing, for instance, a cross platform command-line interface to some remote system.[6] If needed, an applet can leave the dedicated area and run as a separate window. However, applets have very little control over web page content outside the applet dedicated area, so they are less useful for improving the site appearance in general (while applets like news tickers[7] or WYSIWYG editors[8] are also known). Applets can also play media in formats that are not naively supported by the browser[9]

HTML pages may embed parameters that are passed to the applet. Hence the same applet may appear differently depending on the parameters that were passed.

Examples of Web-based Applets include:    QuickTime movies,  Flash movies, Windows Media Player applets, used to display embedded video files in Internet Explorer (and other browsers that support the plug- in), 3D modeling display applets, used to rotate and zoom a model,  Browser games can be applet-based, though some may develop into fully functional applications that require installation.

Applets execute only on the "client" platform environment versus "servlet" and  provides functionality or performance beyond the the browser.  The container restricts applets' capabilities.  Applets are written in a  compiled language, and the scripting language of the container is an interpreted language, and leads to  greater performance or functionality of the applet or  a complete web component can be implemented as an applet.

Java Applet

Java Applets can provide web applications with interactive features above HTML.  Since Java's bytecode is platform-independent, Java applets can be executed by many platforms of browsers. "When a Java technology-enabled web browser processes a page that contains an applet, the applet's code is transferred to the client's system and executed by the browser's Java Virtual Machine (JVM).[10] An HTML page references an applet either via the deprecated <APPLET> tag or via its replacement, the <OBJECT> tag."[11]

 Security

Developments in  coding of applications (mobile and embedded systems) indicate the security of applets.

 Open Platform Applets

Applets in an open platform environment provide secure interactions between applications through a compositional approach and also with advanced compositional verification methods.[12]

 Java Applets

A Java applet contains various security models: unsigned Java applet security, signed Java applet security, and self signed Java applet security.

Web-based Applets

In an applet-enabled web browser security methods counter malicious applets that may cause  denial of service, invasion of privacy, and annoyance.[13]   AppletGuard by monitoring applets can stop malicious applets successfully..[13]


(1) "AskOxford: applet", Oxford Dictionaries. Accessed on July 21, 2009
(2) a b "applet: Definition from Answers.com", Answers.com. Accessed on July 21, 2009
(3)"Oxford English Dictionary". 2011. Retrieved 2011-08-23.
(4) Paul Falstad online applet portal
(5) The virtual hearth
(6) Jraft.com
(7) ObjectPlanet.com, an applet that works as news ticker
(8) Sferyx.com, a company that produces applets acting as WYSWYG editor.
(9) Cortado applet to play ogg format
(10) "Applets", Sun Developer Network. Accessed on July 21, 2009
(11)"HTML applet tag", W3Schools. Access on July 21, 2009
(12) a b Barthe, Gilles; Gurov, Dilian; Huisman, Marieke (2002). "Compositional Verification of Secure Applet Interactions". Retrieved 2010-04-10.
(13)a b Hassler, Vesna; Then, Oliver (1998). "Controlling Applets' Behavior in a Browser". Retrieved 2010-04-10.
(14) <http://en.wikipedia.org/wiki/Applet>. Web. 6 Nov. 2011.
(15)<http://www.oracle.com/us/sun/index.htm>. Web. 5 Nov. 2011.