JSME: a Free Molecule Editor in JavaScript

Background A molecule editor, i.e. a program facilitating input and editing of molecules, is an indispensable part of every cheminformatics or molecular processing system. Today, when a web browser has become the universal scientific user interface, a tool to edit molecules directly within the web browser is essential. One of the most popular tools for molecular structure input on the web is the JME applet. Since its release nearly 15 years ago, however the situation on the web changed and Java applets are facing increasing implementation hurdles due to their maintenance requirements, as well as support and security issues. This prompted us to update the JME editor and port it to a modern Internet programming language - JavaScript. Results The actual molecule editing Java code of the JME editor was translated into JavaScript with the help of the Google Web Toolkit compiler and a custom library that emulates a subset of the GUI features of the Java runtime environment. In the process, the editor was improved by additional functionalities including substituent menu, copy and paste and undo / redo capabilities or integrated help. In addition to desktop system, the editor supports molecule editing also on touch devices, including iPhone, iPad and Android phones and tablets. In analogy to JME the new editor is named JSME. The JSME JavaScript molecule editor is compact, easy to incorporate into web pages and easy to use. Conclusions A free molecule editor written in JavaScript was developed and is released under the permissive BSD license The editor is compatible with JME, has practically the same user interface and similar web API. The JSME editor is available for download from the project web page http://peter-ertl.com/jsme