When we started doing an electronic book on photovoltaics web browsers had very limited capabilities. Java was all the latest technology and so we did the interactive graphs by using a Java plugin. Jeff Cotter did all the coding and the interactive graphs were far ahead of anything else available.
In the intervening years, web browsers became much more powerful and standard compliant making sophisticated graphics possible. Meanwhile Java exhibited an increasing number of vulnerabilities and we see more and more people visiting the website without Java. We estimate a quarter of people have Java disabled or no installation at all.
Due to these two trends we converted all the Java graphs to HTML5. They are viewable on all the major browsers and without any plugin. They even work on the iPad. Jeff wrote such great structed code that the conversion was straight forward and the new frame work is entitled JeffGraph. It is unusual to be able to be use someone elses code but in this case we used it in a different language.
The only disadvantage is that it does not work in Internet Explorer 8 on Windows XP. Those users will have to use Chrome or Firefox to be able to see the new graphs. We estimate that this is less than 10 % of users and it is declining all the time.
We hope everyone enjoys the simplicity of the new JeffGraphs and we welcom suggestions for new graphs.