This tool is great if you want to create classic graphs that show trends over time. The types of graphs that it can produce are similar to those that one can produce in Excel, but are much more interactive. This makes for better data exploration, and often times just for a more clear representation of data in general. All of the graphs that you produce with Highcharts have interesting hover effects, such that hovering over particular data points or lines will show specific values which are useful in exploration and probably also outlier analysis. These effects bring a lot of extra life to the graphs.
This is an extensive and mature product, and therefore it has support forums in addition to support emails, Github reporting, Stack Overflow help, and a book to reference. It is free to use for non-commercial purposes. Interestingly, all the files are downloadable and therefore customizable. This is something that the company markets in particular, because users can use the existing product as a baseline and alter it to fit their specific needs.
The library can be easily incorporated into websites through simple script tags in the HTML headers and can be used in conjunction with jQuery or as a standalone tool. There are a lot of cool demos on the web, a few of them I’ve linked to here: snow depth v time and population growth by religion.
If you’re looking to create simple, classic plots for a quick visualization, this is the product for you. They have a set of standard graphs that are incredibly easy to plug data in and produce yourself.