When comparing Processing.js vs Highcharts, the Slant community recommends Processing.js for most people. In the question“What are the best JavaScript drawing libraries?” Processing.js is ranked 4th while Highcharts is ranked 18th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Good at creating complex visual effects and filters
Pro Fast rendering of complex scenes
Because Processing doesn't keep track of shape objects it's more efficient than other libraries. Processing can do more complicated effects faster than other libraries. Although this means you have to keep track of more yourself in your code, it also means you have more control over the finer details of how things are rendered.
Pro Cross-platform compatibility
In processing you can write code in both JavaScript and Processing code. This allows you to use existing Processing code on the client side.
Processing code is similar to Java in that it has static typing. This can make more complex calculations more robust, and less likely to cause conflicts.
The library takes a more frame based approach to rendering, so you use drawing functions to draw directly to the frame without objects. This can make it easier to write efficient full frame rendering scenes and post processing effects.
Pro Good documentation
Very handy with examples and explanations.
Pro Excellent browser support
Highcharts supports all modern browsers (including IE6 and up), iOS and Android.
Pro Large and active community
Highcharts has a large and supportive community, resulting in a fast response from both stack overflow and the Highcharts forum.
Pro Lots of good examples
The site has a selection of good examples that will help you get started quickly.
Pro Supports multiple Y axes
Important for trend correlation, eg. comparing number of clicks to sale amounts. Not same scales / units.
Pro Library to support Microsoft .NET
Compatable with .NET framework 4+, can develop graphs from server side for ASP .NETand ASP .NET MVC applications.
Cons
Con Processing.js is now archived, and won't be updated
Con Commercial
Highcharts is not free for commercial projects, with a starting price of US$590 for Single Developer + Maintenance & Support
Con The examples are not that great
For instance, example's JsFiddle may get stalled when loading.