History of Formula Applet


2001Formula Applet arises as derivative of a Java applet called HotEqn. HotEqn is able to render TEX code as a graphical formula.

HotEqn applet was only able to create a formula as output. The source code of HotEqn was accessible, so its possibilities were expandable. Formula applet added input by keyboard.

The licence of HotEqn was unclear; clarification was not possible. Therefore, all code of HotEqn was finally dispensed. The formula applet was developed as a stand-alone Java applet.

Originally, HotEqn comes from the Ruhr-University of Bochum (VCLAB). But the links are broken.

2003Formula Applet is presented at lectures (Dillingen, Bayreuth) and on the internet (www.fuemo.de/formelapplet).
2006The Site www.formelapplet.de goes online.
2008Rudolf GroƟmann gets an account at ZUM Wiki wiki.zum.de (German).
Publishing of the GeoGebra Mediawiki Extension.
2010Oracle acquires Sun and with it the rights to Java.
2010Publishing of the Formula Applet Mediawiki Extension.
The Formula Applet is presented at the MNU Franconia Autumn Conference.
2010The site wiki.formelapplet.de replaces the site www.formelapplet.de.
2010-2012A so-called W-Seminar at Gymnasium Stein creates exercises from mathematics, physics and chemistry using the Formula Applet. The exercises are published at the ZUM Wiki. 

W-Seminar (Bavaria, Germany) = science preparatory course

Version 4 of the formula applet (deprecated) still uses Java.

2011Formula Applet does not run on smartphones, because Java applets are not supported in general.
By using the Google Web Toolkit (GWT), it should be possible to make the Formula Applet work on smartphones as well.

The maintenance of the code is getting more and more difficult. (Forking).

Two versions of Formula Applet arise: the so-called “classic” version (using Java) and the “mobile” version (using GWT). It is attempted to use as many classes in common as possible for the two versions.

The use of GWT makes it necessary to use Eclipse for editing instead of JBuilder or NetBeans.

2012-2014A second so-called ‘W-Seminar’ at Gymnasium Stein creates additional exercises using the Formula Applet. Again the exercises are published at the ZUM Wiki.

The exercises are partly taken from the so-called Basic Knowledge Catalogue of Gymnasium Stein.

2014Oracle delivers an update of Java, which causes that only digitally signed Java applets may run. In one fell swoop, over a thousand exercises in the ZUM Wiki become unusable. 

Developers must purchase a signature to digitally sign their applets.

The formula applets still work for those students who have banned an update of Java. This effect makes it difficult to find the cause of the problem.

2014-2015A company from the edutainment sector is interested in the formula applet, which is still “closed source” at the time. Despite a lot of preparatory work, cooperation does not materialise.
2015After dropping the closed-source approach, various foreign libraries (MathJax, Maiden) are tried, to simplify the code responsible for rendering the formula.
2016The formula applet sometimes shows errors – for example, the virtual keyboard freezes.The errors are not reproducible and only occur online. They are related to timing problems when loading the JavaScript libraries. Since the errors do not occur on the local server, debugging is almost impossible.
2017-2018Java applets are no longer supported by current browsers. 

2017:As of version 9, Java applets are marked as deprecated.

2018: Oracle removes the class “Applet” from Java version 11.

See also en.wikipedia.org/wiki/Java_applet

2019A new version is created using JavaScript, the version management system GIT and the editor Visual Studio Code.
2020The Formula Applet becomes open source. It uses some open source libraries: jQuery, MathQuill and Hammer.
2021Formula Applet is published at GitHub: github.com/gro58/FormulaApplet
2022The formula applet will be a new H5P content type. However, it is not yet published in the H5P Hub. A new version of this site now uses WordPress and H5P.